Hello
i logged in for the first time to Steam after around two years of having Manjaro.
i had a black screen instead of the STORE/LIBRARY/etc… overlay,but still could see the upper menus and bottom options.
looking around for a solution,i found that i should try to update the clinet via “Steam/check for client updates” which i did and it installed,and now it works fine.
i was a bit surprised since i thought that in a Linux Distro this should not be possible/or done by the package manager.
I just switched over from windows and this was a common thing after launching steam even on windows, for me just clicking on the library link/menu item would resolve it.
edit: misread the OP. Thought the content was rendered blank and the top list of STORE LIBRARY etc. was still visible.