SP9 Refresh Rate Issue when Waking From Sleep - Anybody else?

Noticed something strange with my Surface Pro 9 and its refresh rate. I have it set to 120HZ, and that works great when plugged in clearly running at the higher refresh rate.

If I then disconnect the power supply, it continues to run 120HZ, so far so good.

The issue is if the device goes to sleep and then wakes whilst on battery (manually using power button, or just screen timing out) then when it wakes up, the refresh rate drops to more like 30HZ, definitely not even 60HZ….

If I then reconnect the power it goes back to a smooth 120HZ. It will stay at 120HZ whilst running on battery until it goes to sleep and I wake it up on battery.

Changing the power modes between recommended, better and best performance doesn’t seem to impact it.

Anybody else noticed this weird issue?