I'm hoping that 10.15.3 which I installed yesterday will help remedy.
Weirdly enough this only happens if I don’t turn off the mac for days (only putting in sleep mode) and when the ram is close to 16GB.
However, when the ram gets to 16GB, the only thing that gets impacted is the video, there is no spinning wheel, audio doesn’t stop. Just the video stutters for a bit, then jumps to present.
The theory here is that the onboard graphics card doesn’t have enough ram for it, it is being swapped constantly, which causes the stutters.
I hope a system update will be enough to fix it.
Edit: adding “no” to spinning wheel
If not, it sounds like a defective unit. I'd strongly recommend taking it to Apple Store.
I had no issues with laggy keyboard input, freezes and battery life was very solid for me. I've returned the laptop not because of these issues but because useless touch bar and large trackpad on top of Catalina issues.
There could also be an issue with your SSD or HDD. To come to a conclusion try putting your SSD to another MB and see wheres the issue
The SSD is soldered directly to the logic board, so that may not be a viable strategy.