I'm on a Ryzen APU too, the Raven Ridge 2500U, and have had an equally disastrous experience on linux. I will say though in the last 6 months I have _finally_ figured out how to make the machine stable and stop randomly crashing. Here's the key, and it might help you to try too:

- Upgrade to _the very latest_ kernels. I'm not kidding, you need to start following mainline stable builds. In Ubuntu or ubuntu-based derivatives check out the ubuntu-mainline-kernel script: https://wiki.ubuntu.com/Kernel/MainlineBuilds I'm on 5.10.4 right now but probably should uprade. You need a _minimum_ 5.4 kernel to fix some egregious instability issues, but in general keep your kernel bleeding edge updated.

- Disable MWAIT instructions. This was the final missing piece of making my machine stable. The TL;DR is that AMD put out errata recently that MWAIT is basically 100% broken on these early Ryzen processors: https://www.amd.com/system/files/TechDocs/55449_Fam_17h_M_00... You can read much more in this enormous kernel bug report: https://bugzilla.kernel.org/show_bug.cgi?id=196683 The fix is to add a "idle=nomwait" flag to your kernel startup.

It's a night and day difference with these fixes in place. I still sometimes get a touchpad lockup on wake from sleep, but it's maybe 1 out of every 50 times and kind of expected for linux. No longer do I have random kernel panic-level lockups every hour. The little laptop just flies and flies with these Ryzen processors.