I just Googled "ryzen temperature monitoring linux".
I've had a Ryzen 1700 since they first came out so I was following the Linux support for that fairly closely at the time, mostly by browsing Phoronix fairly frequently. Thankfully after a few months I didn't need to because things were working pretty well by then, other than the thermal monitoring that took quite a while to land. Linux and brand new hardware rarely seem to get along well regardless of the vendor unfortunately.