Did you ever find a solution to this? I am on a steam deck (also Linux) and having the same problem, the game crashes as soon as I get to the character select screen.
@Schwim I do everything through macros, so I don't use addons, I only have an addon for threat, DPS, Backpacks and nothing more. I play tanks and healers. I hate DPS.
@WiliemDemon For example, playing a DoT tank on Ascension is impossible because no dps will wait for the first tick from the DoT effect (and at the same time the first damage inflicted causes an increased threat)