Everytime I watch something with fast blinking lights (like this) the screen strats flickering.
It occurs only in Opera GX.

Edit: the problem shows up only with at least one other tab open (only in Opera GX).

Go to the WhatsApp web page, click on the lock icon and then on "Site settings". You should be able to allow microphone registration there.

I like it, but it is too black, i'd like it more if you change it in something more colorful/playful idk.