So, it looks like the new Mac update makes it so a mac can identify when you’re trying to take a screenshot on a streaming platform. Any idea how to get around that?
Now when I screenshot it just comes up as a black page.

In the words of Apple support communities: "I have this problem too."

At least for Netflix, I was able to make screencaptures on Chrome until now. Five months ago it was still working:
http://www.imcdb.org/movie.php?id=15387774

@gamer, I ended up finding a workaround if you want to go back to using chrome. On Chrome go to Settings > Advanced > System - Then turn off 'Use Hardware Acceleration when available'

So I bought a new desktop (RIP old faithful, you will be missed) with Windows 11, but unlike my old Windows 10, which none of the streaming services gave two craps of me taking screenshots, practically all the streaming services that I usually use to take screenshots now seems to block my attempts to take a screenshot. I even tried to do what @reck961 did as well as trot out Snipping Tool to no avail. Is there any other possible workaround(s) available?

OK... Not the perfect solution, but I managed to find an extension tool for Chrome that would take screen shots of Prime and other streaming services (Screenshot Tool).

P.S. I finally re-added an adblocker (Ublock Origin) and it turns out it also kills whatever was blocking me from screenshotting Prime Videos. Haven't checked the other sites yet though.