The 1st of my pair is the same model and I am not experiencing that issue. I am using it with YTTV as well, and have it streaming for many hours on end. Hmm, not sure what to suggest but just wanted to offer up my experience for comparison.
I was thinking of replacing it with the 4K version if only for, I dunno, speed (?) but this one is performing admirably without any hiccups so I don’t really see the point. I’ll keep an eye on it though. My other device is the Onn box and it seems to me that its performing identically. At least I can’t tell the difference between them.