I went over the word/letter cap link with all needed information.
Try,
Open Steam
Go to Steam in top left corner,
Go to Settings,
Under Account look for Beta Participation
Change that to NONE,
Let steam update
Not too sure this will help.
I’ve been having the same problem, only it stopped doing it for like 2 times and let me play, then it started again and I haven’t been able to fix it since