I would like to thank @TheLinuxNinja for posting what was for me the solution to the issue described by @parol.
I recently bought an Asrock Deskmini x300 with an AMD Ryzen 5 3400G. I installed Linux Mint 20 Cinnamon, v4.6.7, Linux Kernel 5.4.0-60-generic. I experienced the same problems, so I...