Same problem here. Kernel 5.2.x makes my MT76x2 wifi very unstable, with bad performance and lot of dropouts. Running 4.19.x for now.
> I am using Sid on my laptop (HP ZBook 15) and since first linux-image-5.2.0-1 > and then linux-image-5.2.0-2 > the wifi is not stable and goes down after few seconds.