Is anything of you setup that stands out? Are you running with super sampling (using nvidia settings), multiple screen etc?
I’ve tested this quite alot and never recieved anything else than the previous resolution.
Happens to me on tons of games. Probably because of what Axloss said. I just hit ALT + Enter, the big enter not the Numpad one and it fixes it.
Since I run borderless full screen now though, it doesn’t happen.
ALT + ENTER is expected to be undefined behaviour atm but not ALT + TAB since we control the resolution manually during ALT+TAB but not ALT+ENTER (windows, drivers etc decide for that case).
I have a repro for one case when this happens. I will solve that one and then see if that resolves your issue.
In my case I use Nvidia DSR to supersample the game.
We have done some changes regarding alt+tab with WoM release
any way, I’ve done a couple of fixes for a few scenarious were we ended up with wrong resolution.
This will come with next patch I would guess. I hope this fixes your issues.
is it resolved for you?
great 
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