TeXstudio not recognizing custom commands

Question

I have been trying to implement the code given in the answer by percusse in \foreach with \newcommand how to use them together?. The code seems to work, however TeXstudio does not recognize the new commands (i.e. in highlights them orange).

Here is the code in my situation:

\foreach \x in {A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}{
    \expandafter\xdef\csname cal\x\endcsname{\noexpand\mathcal{\x}}
    \expandafter\xdef\csname scr\x\endcsname{\noexpand\mathscr{\x}}
    \expandafter\xdef\csname frak\x\endcsname{\noexpand\mathfrak{\x}}
}

which allows me to write things like $\calA$ to display mathcal A. However, the \calA appears as an "unrecognized command" (i.e. it is highlighted orange) in TeXstudio.

I have all of the usual packages like amsmath, amsfont, amssymb, etc. loaded.

Question: how can I get these custom commands to be recognized by TeXstudio?

---

For clarity, here is all of the packages that I have loaded:

%---------------------------------------------------------------------------
%                           DOCUMENT CLASS
%---------------------------------------------------------------------------
\documentclass[12pt, letterpaper, leqno]{amsart}
\usepackage[letterpaper, margin=1in]{geometry}
\usepackage[utf8]{inputenc}
\usepackage[foot]{amsaddr}
%---------------------------------------------------------------------------
%                             BIBLATEX
%---------------------------------------------------------------------------
\usepackage[style=alphabetic, maxnames=99]{biblatex}
\AtBeginBibliography{\small}
\usepackage{microtype}
\microtypesetup{protrusion=false}
%---------------------------------------------------------------------------
%                             HYPERREFS
%---------------------------------------------------------------------------
\usepackage{xr-hyper}
\usepackage{xstring}
\usepackage{hyperref}
\usepackage{url}
\hypersetup{
    colorlinks   = true, 
    urlcolor     = cyan, 
    linkcolor    = blue, 
    citecolor   = blue 
}
\makeatletter
\newcommand{\labeltext}[3][]{%
    @bsphack%
    \csname phantomsection\endcsname% in case hyperref is used
    \def\tst{#1}%
    \def\labelmarkup{}% How to markup the label itself
    %\def\refmarkup{\labelmarkup}% How to markup the reference
    \def\refmarkup{}%
    \ifx\tst\empty\def@currentlabel{\refmarkup{#2}}{\label{#3}}%
    \else\def@currentlabel{\refmarkup{#1}}{\label{#3}}\fi%
    @esphack%
    \labelmarkup{#2}% visible printed text.
}
\makeatother
%---------------------------------------------------------------------------
%                        FONTS AND MATH PACKAGES
%---------------------------------------------------------------------------
\usepackage[english]{babel}
\usepackage{amsfonts}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{amssymb}
%\usepackage{mathabx}
\usepackage{mathrsfs}
\usepackage{xpatch}
\usepackage{stmaryrd}
%---------------------------------------------------------------------------
%                       TIKZ AND DIAGRAMS PACKAGES
%---------------------------------------------------------------------------
\usepackage{tikz}
\usepackage{tikz-cd}
\usetikzlibrary{arrows.meta,automata,positioning}
\usetikzlibrary{svg.path}
\usepackage{amscd}
\usepackage{quiver}
\usepackage{tikzit}
%---------------------------------------------------------------------------
%                     TABLES, FIGURES, LISTS PACKAGES
%---------------------------------------------------------------------------
\usepackage{float}
\setcounter{MaxMatrixCols}{15}
\usepackage{enumitem}
\usepackage[labelfont=bf]{caption}
\usepackage[linewidth=0pt]{mdframed}
\usepackage{subfig}
%---------------------------------------------------------------------------
%                    HEADERS, FOOTNOTES, CHAPTERS, ETC. PACKAGES
%---------------------------------------------------------------------------
\usepackage{fancyhdr}
\usepackage[bottom, perpage]{footmisc}
%\usepackage{titlesec}
\usepackage{etoolbox}
%_____Bold sections
\patchcmd{\section}{\scshape}{\bfseries}{}{}
\makeatletter
\renewcommand{@secnumfont}{\bfseries}
\makeatother
%_____Minimal spacing chapter titles
%\titleformat{\chapter}[hang]{\huge\bfseries\doublespacing}{\thechapter}{20pt}{}{}
%\titlespacing*{\chapter}{0pt}{-30pt}{40pt}
%---------------------------------------------------------------------------
%                           GENERAL FORMATTING
%---------------------------------------------------------------------------
\allowdisplaybreaks
\usepackage{subfiles}
\usepackage{setspace}
%\doublespacing
\setlength{\parskip}{0.25em}
%_____Numbering equations, figures, and theorems all the same by section
\numberwithin{equation}{section}
\numberwithin{figure}{section}
\makeatletter
\let\c@equation\c@figure
\makeatother
%---------------------------------------------------------------------------