It doesn't happen on the GTX 660. I'm playing in 1920x1080. Also tried some odd resolutions via DSR, and it doesn't happen.

Hello,
I'm afraid I won't be able to test this anymore, because I've sold my GTX 460 and I think it doesn't occur on newer series graphics cards. I will most likely be able to get a GTX 660 next week and I will test it again. I will report back if I don't forget it.

So I've disabled the Nvidia DSR.
And for some reason, the -disable3DRatioCheck parameter doesn't work on experimental branch.
But on stable it worked, and it enabled lower resolutions than 1280x1024 (1280x960, 1280x800, 1280x720, 1152x864, 1024x768 etc.).
But the problem still persists with this configuration, and now it doesn't matter how/how many times I change resolution (e.g. 1280x1024 -> 1024x768 -> 1152x864), the lighting doesn't get fixed. Even if I switch to windowed mode a few times and back, the lighting remains buggy.
During this, the FPS didn't change. It was 35-45 FPS all the time, like always (I was in Elektro). This indicates that the FPS only drops when the lighting gets unbugged.
So, then I re-enabled Nvidia DSR, and I could reproduce the fix (by switching to a higher than native resolution and back to original, also switching to windowed mode, because sometimes it only works when I also do that).

Also, after the "fix", the game game runs very poorly. It gets progressively worse and worse, and the worst it gets is around 12 FPS. Before the "fix", the game runs the same as 0.60 (40-60 FPS in cities, 60-120 outside cities).

No, dynamic super resolution just enables me to change resolution to other than 1280x1024. It's not the DSR itself, but the sequence of changing the resolution to any other than what the game starts in, and then back to it.

I just tested this again after a long time, and the issue seems to be solved after I change the resolution to any other. I can even change it back to the original without it happening again.

What surprises me, is that yesterday I gave my account to my buddy to play, and he downloaded 0.60, not 0.61, and after removing and taking his pants, his face became black.
I thought this bug came with 0.61, and I've never seen it before in 0.60, and now after 0.61 released, this bug is in 0.60 too?
And yes, I'm completely sure he was playing 0.60. He didn't switch to experimental, and I remember he had the old server browser before joining, and it was also not an experimental server.

I think it happens after ~50 minutes of playtime. I just had it after the second time of playing more than 50 minutes.
Lag becomes more and more severe, until my character's movement becomes jittery, and then after ~15 more minutes it gets so severe that the aspect ratio starts acting up.

I think the flickering or sometimes just black terrain at night is also caused by the same bug as the black face. The lighting doesn't affect the terrain and the character's face.

https://feedback.bistudio.com/T120816

I've just tried it in today's test, and the issue is still there in build 135869.