Steinberg UR12 clicks and sound losing

Hello, everyone. The problem is seen in the headline. But I need to explain more.
My audiointerface can click and lose sound while watching videos and listening to music. It depends on buffer size I set. The more buffer size is, the more latency is. Maybe UR12 is too weak? I can connect my electroguitar to it and hear clicks and sound losing over time.
I set it up like everyone writes and shows.
Maybe my PC has problems?
Params: AMD FX 8300 8 cores, 16GB RAM, Motherboard Model: ASUS M5A78L-M PLUS/USB3
It’s not weak, I guess, but I don’t know the direction to dig to.
Can you help me set everything up? Maybe I need a new audiointerface? If yes, what model do I need?
Thank you.