Thanks for the information and understanding!
We have a possible theory that should be easy enough to test. Since you have a MacBook Pro with both Intel and AMD graphics, the system is designed to dynamically switch between these two GPUs. There’s a setting to disable this, I’m curious if this would have any effect on the lagging issues if you have a moment to test this out. To turn off GPU switching see here: https://support.apple.com/en-us/HT202043
This will tell the system to only use the AMD graphics, which when using the dock may be preferable since that GPU is far more powerful. If there’s no change, we’ll have to keep investigating.
Happy Thanksgiving to you as well!
Josh