I update the TeX Live 2019 on my computer today. Then the behavior of \bfdefault and \bfseries changed, see the next MWE:
\documentclass{article}
\begin{document}
\bfdefault\\
{\fontseries{\bfdefault}\selectfont TEXT}\\
{\bfseries TEXT}
\end{document}
The result before updating:
The \bfdefault was bx and it changed to b.
The \bfseries is not equivalent to \fontseries{\bfdefault}\selectfont after updating.
Is this a bug? Or something else?
