bytefield package \rightwordgroup misaligned curly bracket when compiling with LuaLaTeX

Question

I am using the bytefield package and am following the example listed on page 7 of the the package documentation on CTAN. Creating the following MWE from the code I get the result below:

\documentclass[12pt,a4paper]{article}
\usepackage{bytefield}
\begin{document}
\begin{bytefield}{16}
\bitheader{0,7,8,15} \
\begin{rightwordgroup}{Header}
\bitbox{4}{Tag} & \bitbox{12}{Mask} \
\bitbox{8}{Source} & \bitbox{8}{Destination}
\end{rightwordgroup} \
\wordbox{3}{Data}
\end{bytefield}
\end{document}

As you can see the top of the curly bracket is not properly aligned. As a comparison, here is what this code should compile to according to page 8 in the manual:

Any advice on how to fix that issue would be greatly appreciated.

(I am using Tex Live on Windows 10 with version 2.6 of the bytefield package)

Edit:

As requested, here is the logfile:

This is LuaHBTeX, Version 1.13.2 (TeX Live 2021/W32TeX)  (format=lualatex 2021.5.26)  16 AUG 2021 14:22
 restricted system commands enabled.
**mwe.tex
(./mwe.tex
LaTeX2e <2020-10-01> patch level 4
Lua module: luaotfload 2021-05-21 3.18 Lua based OpenType font support
Lua module: lualibs 2021-05-20 2.74 ConTeXt Lua standard libraries.
Lua module: lualibs-extended 2021-05-20 2.74 ConTeXt Lua libraries -- extended c
ollection.
luaotfload | conf : Root cache directory is "C:/texlive/2021/texmf-var/luatex-ca
che/generic/names".
luaotfload | init : Loading fontloader "fontloader-2021-05-20.lua" from kpse-res
olved path "c:/texlive/2021/texmf-dist/tex/luatex/luaotfload/fontloader-2021-05-
20.lua".
Lua-only attribute luaotfload@noligature = 1
Lua-only attribute luaotfload@syllabe = 2
luaotfload | init : Context OpenType loader version 3.116
Inserting `luaotfload.node_processor' at position 1 in `pre_linebreak_filter'.
Inserting `luaotfload.node_processor' at position 1 in `hpack_filter'.
Inserting `luaotfload.glyph_stream' at position 1 in `glyph_stream_provider'.
Inserting `luaotfload.define_font' at position 1 in `define_font'.
Lua-only attribute luaotfload_color_attribute = 3
luaotfload | conf : Root cache directory is "C:/texlive/2021/texmf-var/luatex-ca
che/generic/names".
Inserting `luaotfload.harf.strip_prefix' at position 1 in `find_opentype_file'.
Inserting `luaotfload.harf.strip_prefix' at position 1 in `find_truetype_file'.
Inserting `luaotfload.harf.finalize_vlist' at position 1 in `post_linebreak_filt
er'.
Inserting `luaotfload.harf.finalize_hlist' at position 2 in `hpack_filter'.
Inserting `luaotfload.cleanup_files' at position 1 in `wrapup_run'.
Inserting `luaotfload.harf.finalize_unicode' at position 1 in `finish_pdffile'.
Inserting `luaotfload.glyphinfo' at position 1 in `glyph_info'.
Lua-only attribute luaotfload.letterspace_done = 4
Inserting `luaotfload.aux.set_sscale_dimens' at position 1 in `luaotfload.patch_
font'.
Inserting `luaotfload.aux.set_font_index' at position 2 in `luaotfload.patch_fon
t'.
Inserting `luaotfload.aux.patch_cambria_domh' at position 3 in `luaotfload.patch
_font'.
Inserting `luaotfload.aux.fixup_fontdata' at position 1 in `luaotfload.patch_fon
t_unsafe'.
Inserting `luaotfload.aux.set_capheight' at position 4 in `luaotfload.patch_font
'.
Inserting `luaotfload.aux.set_xheight' at position 5 in `luaotfload.patch_font'.
Inserting `luaotfload.rewrite_fontname' at position 6 in `luaotfload.patch_font'
. L3 programming layer <2021-05-25>
(c:/texlive/2021/texmf-dist/tex/latex/base/article.cls
Document Class: article 2020/04/10 v1.4m Standard LaTeX document class
(c:/texlive/2021/texmf-dist/tex/latex/base/size12.clo
File: size12.clo 2020/04/10 v1.4m Standard LaTeX file (size option)
luaotfload | db : Font names database loaded from C:/texlive/2021/texmf-var/luat
ex-cache/generic/names/luaotfload-names.luc)
\c@part=\count177
\c@section=\count178
\c@subsection=\count179
\c@subsubsection=\count180
\c@paragraph=\count181
\c@subparagraph=\count182
\c@figure=\count183
\c@table=\count184
\abovecaptionskip=\skip47
\belowcaptionskip=\skip48
\bibindent=\dimen138
)
(c:/texlive/2021/texmf-dist/tex/latex/bytefield/bytefield.sty
Package: bytefield 2020/10/31 v2.6 Network protocol diagrams
(c:/texlive/2021/texmf-dist/tex/latex/tools/calc.sty
Package: calc 2017/05/25 v4.3 Infix arithmetic (KKT,FJ)
\calc@Acount=\count185
\calc@Bcount=\count186
\calc@Adimen=\dimen139
\calc@Bdimen=\dimen140
\calc@Askip=\skip49
\calc@Bskip=\skip50
LaTeX Info: Redefining \setlength on input line 80.
LaTeX Info: Redefining \addtolength on input line 81.
\calc@Ccount=\count187
\calc@Cskip=\skip51
)
(c:/texlive/2021/texmf-dist/tex/latex/graphics/keyval.sty
Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
\KV@toks@=\toks15
)
\bytefield@height=\skip52
\bytefield@height@increment=\skip53
\entire@bytefield@picture=\box47
\bf@bitwidth=\skip54
\bf@bitheight=\skip55
\units@wide=\skip56
\units@tall=\skip57
\units@high=\skip58
\header@xpos=\skip59
\c@header@val=\count188
\c@max@header@val=\count189
\curly@box=\box48
\wordlabelr@start=\skip60
\wordlabelr@end=\skip61
\wordlabell@start=\skip62
\wordlabell@end=\skip63
\total@lbox@width=\skip64
\label@box@width=\skip65
\label@box@height=\skip66
\word@label@box=\box49
)
(c:/texlive/2021/texmf-dist/tex/latex/l3backend/l3backend-luatex.def
File: l3backend-luatex.def 2021-05-07 L3 backend support: PDF output (LuaTeX)
\l__color_backend_stack_int=\count190
\l__pdf_internal_box=\box50
)
(./mwe.aux)
\openout1 = mwe.aux
LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for TS1/cmr/m/n on input line 5.
LaTeX Font Info:    Trying to load font information for TS1+cmr on input line 5
.
 (c:/texlive/2021/texmf-dist/tex/latex/base/ts1cmr.fd
File: ts1cmr.fd 2019/12/16 v2.5j Standard LaTeX font definitions
)
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for TU/lmr/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
\width=\dimen141
\height=\dimen142
\depth=\dimen143
\totalheight=\dimen144
LaTeX Font Info:    External font cmex10' loaded for size (Font) &lt;12&gt; on input line 10. LaTeX Font Info: External fontcmex10' loaded for size
(Font)              <8> on input line 10.
LaTeX Font Info:    External font `cmex10' loaded for size
(Font)              <6> on input line 10.
\width=\dimen145
\height=\dimen146
\depth=\dimen147
\totalheight=\dimen148
\width=\dimen149
\height=\dimen150
\depth=\dimen151
\totalheight=\dimen152
\width=\dimen153
\height=\dimen154
\depth=\dimen155
\totalheight=\dimen156
\curly@height=\dimen157
\half@curly@height=\dimen158
\curly@shift=\dimen159
\total@box@width=\dimen160
\width=\dimen161
\height=\dimen162
\depth=\dimen163
\totalheight=\dimen164
 [1
{c:/texlive/2021/texmf-var/fonts/map/pdftex/updmap/pdftex.map}] (./mwe.aux))
Here is how much of LuaTeX's memory you used:
 776 strings out of 478296
 100000,383344 words of node,token memory allocated
 646 words of node memory still in use:
   13 hlist, 2 vlist, 2 rule, 6 math, 2 glue, 3 kern, 6 glyph, 9 attribute, 55 g
lue_spec, 9 attribute_list, 1 write nodes
   avail lists: 2:271,3:18,4:2,5:90,6:12,7:466,8:3,9:322,11:6
 21014 multiletter control sequences out of 65536+600000
 34 fonts using 2864419 bytes
 42i,11n,50p,123b,301s stack positions out of 5000i,500n,10000p,200000b,80000s
<c:/texlive/2021/texmf-dist/fonts/opentype/public/lm/lmroman12-regular.otf><c:/t
exlive/2021/texmf-dist/fonts/opentype/public/lm/lmroman6-regular.otf><c:/texlive
/2021/texmf-dist/fonts/type1/public/amsfonts/cm/cmex10.pfb>
Output written on mwe.pdf (1 page, 14454 bytes).
PDF statistics: 26 PDF objects out of 1000 (max. 8388607)
 15 compressed objects within 1 object stream
 0 named destinations out of 1000 (max. 131072)
 1 words of extra memory for PDF output out of 10000 (max. 100000000)