Windows 10 - White bar on top of Windows Screen

Hello Guys hope all of you are fine
Attention, please.

Since morning guys one of my friends has faced all kinds of random issues. Although he has seen this issue for another workstation in the past.
My friend’s machine; HP EliteDesk 800 G5 SFF; Windows10 and he believe version 2004; dual monitor.
The issue on my friend’s machine is a white bar on top- meaning he cannot see the minimize, maximize, or close button when using file explorer or browser, etc.
Basically from the address bar and above is a whiteout. But there is a solution I have found that whenever unless F11 twice then we can see those.
He searched, tried, and asked about that type of issue from anyone and anywhere, but couldn’t found anything about that.
Thus Anyone faces this type of issue in the past
Thus anybody has any type of solutions
Please guide us.
Thanks a lot