@mandricus - you might instead try editing your ESO UserSettings.txt file so this setting is "4":Tried that, It doesn't work for me. It's still in window mode.
Moreover, the game always crash on start in my MacBook Pro 2018 (hexacore i7). In order to be able to run it, I have to disable two cores with cpusetter.
@mandricus - you might instead try editing your ESO UserSettings.txt file so this setting is "4":
SET MaxCoresToUse.4 "4"
There have been some problems in the past like you report that this worked around, and it may be more tolerable than affecting your whole system.