Had a Dell XPS 13 9360 which brightness randomly will become darker.. saw the below 2 links and not sure if that would resolve the issue.. as the solution seems like not confirmed.
A lot of laptops have adaptive brightness now. That 2nd reddit link of yours should lead you to the correct answer too.
grnow
ASKER
thanks for the suggestion, user called DELL support for assistance and some steps on bios given however issue still not yet resolved.. will see if any further updates as laptop currently overseas
John
If Dell cannot fix it then there may be a hardware problem requiring service