Did you enable camera2api on your phone is yes. How?
Nothing aside in the settings you can see in the screenshot in my earlier post.
The only thing I did may be differently before installation was to turn off the hdr in the build in camera app as per advise from somewhere. After that I went and turn it on and there were no problems at all. So now I have normally working samsung camera app and the gcam one. I can switch whatever I want in the apps and there are no problems.
I also have another camera app - CameraZoomFX (paid) with turned on Camera2 API and it also work ok with every available setting. I have even used them all at the same time to test what would happen - well nothing really. Everything works ok.