AMD GPU fluctuates utilization and clock speed on restart
AMD has a feature called "Cool and Quiet" which a lot of people have been having issues with lately.
- Make sure you have the latest chipset drivers installed.
- According to this post by an AMD employee, monitoring tools such as CPU-Z can screw up the Cool and Quiet feature. They recommend AMD Ryzen Master Utility
- If all else fails, you can disable the feature in the BIOS. You could also try setting "Power Plan" to "High Performance" in Windows (Control Panel --> Power Options --> Advanced). Note that both of these will reduce battery times.