Comment 1 for bug 1863489

powertop:
Take care, maybe you have to scroll down, it is in the middle row below the cpu-cores
For some strange reason also the packet (summery?) shows in all states 0%, although I can observe the individual CPU cores are in different power states.

Edit:
I observed that with Ubuntu Mate 18.04 with new (!) installations. My old installation (kernel 4.15 seems not to be updated to newer version) is not suffered. I have tested also Linux Mint 19.3. Initially (kernel 5.0 if I remember right works) but after update to 5.3 not anymore. So I can exclude hardware as an issue.