This seemed to be my issue as well. Not only while gaming, but also while watching videos and general use as well. Found a very similar solution and I used these settings:
echo manual > /sys/class/drm/card1/device/power_dpm_force_performance_level
echo performance > /sys/class/drm/card1/device/power_dpm_state
echo 1 > /sys/class/drm/card1/device/pp_power_profile_mode

Setting to manual instead of high is supposed to lower power usage when the pc is idle or not working as hard.

Kudos to this thread - https://www.reddit.com/r/linux_gaming/comments/zp5prc/fix_for_low_fps_and_stutteringjittering_on_amdgpus/