Lightmaps randomly switching to lower resolution

hello

i got a little bit of a problem that only occurs in packaged builds
it seems that the lightmaps switch to lower resolutions when walking around (and sometimes while standing still) and switch back again to their normal resolution after a while, and then the same keeps repeating
this does not happen in PIEs, only in builds


I also am getting screen tearing (what seems to be vsync issue), i tried console command t.maxfps 60 but to no avail
this also only happens in builds full screen but not while windowed, and never in PIEs be it windowed or full screen

any suggestions to what is causing these issues in builds?

Edit: ok i managed to solve the vsync issue, my nvidia control panel vsync settings was on adaptive and had to switch it to “use 3d application settings” and then use r.vsync 1 command to get rid of the screen tearing issue
i still would love to hear about how to solve the lightmaps issue mentioned above