My issue is that the code completion does not show me suggestions for C functions, for example when I type "sca", or "scan" it does not show any function suggestions at all (I wanted it to show scanf). I run codeblocks.exe from C:\Program Files\CodeBlocks. Also, if I run the CbLauncher.exe file from the same folder it shows me scanf, printf and other C functions. Before this issue I have used Codeblocks on the same PC, so I might have changed by mistake some settings which caused this issue.
I reinstalled Codeblocks from the official site, binary releases for Windows, codeblocks-20.03mingw-setup.exe.
Later Edit: the C functions work properly even though they don't show up in the code completion suggestions.