Hello since I have a 4k screen and a new computer the following is happening in Blender. Depending on the zoom on an object or whether or not faces are selected, etc. my blender becomes darker. If this is a known option I would like to deactivate it
That might be your 4K monitor...
My 4K monitor tends to darken really soon, if it thinks nothing is happening on the screen...it seems to go into energy saving mode....it can (in the case of my monitor) take a few (lot of) seconds to 'wake up' again.
I don't think it has anything to do with Blender.