Weird flickering issue with Background setting (WS2812B Strip)

Created by: Zeragonii

Finally got my damn WS2812B strip working with a NodeMCU (Took about 5 minutes of actual thinking and I feel a right moron for it.) But now, the strip reacts beautifully to music but when I set a background it flickers like a strobe light at a rave. I've got a 70A 5v PSU (Felt like I didn't want to run the risk of overloading it so I went overboard.) The PSU supplies a stable 5.2V and the strip seems to be ok with that, however I'm yet to be able to explain why it flickers sometimes. I don't know if it's noise on the data line or voltage degradation down the strip but I am completely stumped on this issue and it's the final hurdle before I can make a permanent light fitting out of this setup.