Ubuntu Crashes regularly

[archimedes1981]

I built a Ryzen 3 2200G system a while back and I rarely use it but when I do it practically always crashes.
I'd like to solve it but I lost touch with linux for a while and am sort of lost at the moment.
I opened the logs but couldn't figure out anything.
Anybody can help?
At the moment it freezes everytime I shoot the same guy in Tomb Raider. I don't thinik it's the game because it also freezes while youtube is playing.
Might be graphics related. I only use the Vega graphics on chip and have no overclocking or weird settings. I also just updated the bios for my mobo Which is an ASUS B350M-A.
Any help really appreciated. Please be specific because I reverted to noob level here.

[thehipho]

Does this happen often or only during high CPU?
Test with another OS, to eliminste hardware issues?
Post output of sensors:

sudo apt install lm-sensors
sensors-detect
sensors