Yes, this is another gtk3 issue or a bug in wxGTK/wxWidgets.
Can you please log it in https://sourceforge.net/p/codeblocks/tickets/ ?
Both these versions are affected:
wxWidgets Library (wxGTK port)
Version 3.0.5 (Unicode: wchar_t, debug level: 1),
compiled at May 11 2021 13:25:09
Runtime version of toolkit used is 3.24.
Compile-time GTK+ version is 3.24.29.
wxWidgets Library (wxGTK port)
Version 3.1.6 (Unicode: wchar_t, debug level: 1),
compiled at May 28 2021 13:32:32
Runtime version of toolkit used is 3.24.
Compile-time GTK+ version is 3.24.29.