It's still unknown if it's a bug or a feature, but apparently you will be banned from online gameplay in Soul Calibur VI if you play it on Linux. The ban even affects your whole account, so will still lock you out of the online features even when you boot up in Windows.
As PCGamesN reported, if you launch Soul Calibur VI using Steam Play on Linux, the game will forbid you from playing online. You can't lift the ban even when you reinstall the game nor installing it on a different PC either.
So far there has been no response from Bandai Namco, but the Steam forums have been hot with speculations, with some pointing to Denuvo's DRM protection as the culprit. The Steam Linux tools itself is still in beta, so there are plenty of bugs to be expected too.
Let's hope Bandai Namco will repair this weird bug in the near future, and to be safe, don't start the game on Linux for now.
Have you been affected by this?