When I'm recording with Plays.tv, it also records my steam overlay (When I click SHIFT+TAB.) Is there any way to disable that (So it doesn't record my overlay)
It would majorly depend on how it's recording the Steam Overlay. Can you let me know the following?:
For your issue, I'd highly recommend creating a support ticket with logs. Since you're not using a laptop, it can be more difficult to determine (but definitely not impossible). It would just depend on what the game and Playstv are using for encoding.
Feel free and post back here once you've made it.
Just made it