MacBook – Graphics performance drop after waking from sleep in Catalina (MacBook Pro)

I installed MacOS Catalina last week. I restart my MBP and everything's great, then at some point I either close the lid or just lock the screen for a few hours (sometimes not even a full hour) and after that, graphics performance seems to have dropped.

Symptoms include slow vim (e.g., moving the cursor around), sluggish animations in Safari (e.g., opening and closing tabs), slow transitioning between workspaces, choppy animations when minimising applications.

I've seen some people suggest to reset the NVRAM, but I'd rather not do it until someone confirms that to be the solution.

I had first described this issue in this post in the Apple Support Communities: https://discussions.apple.com/thread/8614302. Sometimes a minor MacOS update would seem to fix it, and then another update would seem to reignite the issue.

Here are the specs:

Product:
  Model Name:   MacBook Pro
  Model Identifier: MacBookPro11,4
  Processor Name:   Quad-Core Intel Core i7
  Processor Speed:  2,2 GHz
  Number of Processors: 1
  Total Number of Cores:    4
  L2 Cache (per Core):  256 KB
  L3 Cache: 6 MB
  Hyper-Threading Technology:   Enabled
  Memory:   16 GB
  Boot ROM Version: 195.0.0.0.0
  SMC Version (system): 2.29f23

Mac OS:
  10.15.1

EDIT: after searching around some more I found this Reddit post and as the user here shows his GPU performance drops to 0.2 GHz. I installed Intel Power Gadget and behold I'm also at 0.2 GHz after having the "bad wake from sleep" problem. Maybe this can be fixed by somehow bumping performance back to the regular value?

EDIT2: my problem is different from Serious Performance Problems using Expose in Catalina because the issues in the other question seem much more severe and include symptoms like extreme temperatures and unusable UI. The other question's issue seemed to be centered around overheating due to dust and bad thermal paste.