The screen brightness reduces automatically after switching from a light mode app to a dark mode app and vice-versa. The brightness slider doesn't move an inch from the previous position. It may be some kind of screen flickering. This is happening after the May 2020 update. Deleted and installed the same updated intel graphics driver and the problem persists. It was not happening on the 1909 update with the same updated graphics driver.
Download, run, and save the results of this utility as a text file:
Then ATTACH the text file (using the paperclip under the toolbar).
Thank you for posting your question on this Intel® Community.
We found another ticket describing the issue reported in this thread. Our recommendation is that you continue troubleshooting this issue with the Intel Customer Support team in your region.
We will close this thread to avoid duplication of effort.
Intel Customer Support Technician