Can't record video on a window while doing something else

[Shylos]

My problem is the following: I usually record my university classes while I'm doing something else with my computer (I have a laptop), so I can watch the video later. I use window capture and it goes well while I'm inside the window, but when I move to another window (for example, I open a pdf) then it stops registering the video. It records the window but not the video or stream that is going on. This happens with my browser, and I tried 3 different ones. As a result, I can't do anything else when I'm recording.
Can you please help me solve this issue?

 

[R1CH]

Modern browsers stop displaying video in the background to save power. In Chrome you can turn it off at chrome://flags/#calculate-native-win-occlusion, not sure about others.

 

[Shylos]

Modern browsers stop displaying video in the background to save power. In Chrome you can turn it off at chrome://flags/#calculate-native-win-occlusion, not sure about others.

It was exactly that. Now it works.Thank you very much.