A little while ago I pointed that Solus users (at least several, myself included) were experiencing issues to run modern versions of Proton following 5.13 (and the introduction of the new vessel technology with Soldier). In other words, no games actually launched with 5.13 versions of Proton on Solus - you had to manually select an earlier version of Proton in order to keep running the games you wanted. This issue lasted for several months.
I am glad to report Solus has fixed the issue - I tried with the recent Proton 6.3 many titles on my Solus machine, and they now all work well and just like expected - and you can know enjoy the improvements brought by the more recent Proton versions. So if you were considering Solus and wondering if that Steam issue still exists - well, it’s gone, so feel free to try it out!