LED Backlight Strips on TV Causing External Speaker Interference
Chances are that the the USB power and the AUX output of your TV share the same 5V power rail. When you connect the LEDs, you either overwork the power supply or some power modulation from the LEDs makes it's way through the power rails into your audio output.
One thing you could try to decouple the audio output by using a isolation transformer. Something like this perhaps https://www.amazon.com/C2G-40000-Extension-Isolation-Transformer/dp/B0047AKVYO (no endorsement intended, illustration only) .
You should check that LEDs don't draw more power than what your TV USB output is rated for. That would be 2.5W for &quot;old&quot; USB and 4.5W for USB 3.0 and up. If your handy with electronic stuff, there are few things with capacitors and resistors you can try, but that would probably be a better fit for https://electronics.stackexchange.com/