Stuttering preview playback (and strange "fix") in After Effects

[VFXbear]

I'm currently on After Effects CC 2020, and there's a nagging problem while using the preview:
The playback stutters and sometimes drops to just below normal playback speed.
The clip I'm trying to view is cached (green line in Timeline), and yet : stuttering playback.
BUT here's the real funny thing : when you click and hold the Fast Previews dropdown menu, the playback levels out, and becomes rocksolid as it should be.  Let go of the window, and the playback goes back to stuttering.
I'm attaching a video where you can clearly see that my selected work area is completely pre-cached, there are no drop frames specified in the Preview panel.
Watch carefully when I click the dropdown menu : you can clearly see the arrow animation become smooth.  When I let go : back to choppy playback.

https://youtu.be/DqhW2vPm-GY 

My setup :
MacPro 5,1
2 x 3.46 Ghz 6-Core
32 GB Memory
Sapphire Pulse RX 580 (8 GB)

[OzM]

I'm having the same issue, and this Fast Previews trick works for me too.

Many thanks! Seriously though - this bug is breaking the core functionality of After Effects, and has been happening on and off for years now. There should be serious resources put into fixing this.

I'm using 16.1.3 running on a late 2013 Mac Pro running Mojave.

[VFXbear]

Anyone else noticed this problem? Anyone? Bueller? Anyone?

[VFXbear]

UPDATE:

it seems there is some sort of "window focus" bug in the cached preview.  Here's an interesting "fix" I discovered to remedy the stuttering:

while the cached preview is running, click the preview options under the main screen and select the bottom "preferences" option. This will open a small breakout window with a drop down.  What's in it is not important, HOWEVER: your preview is now running smooth in the background without having to keep the preview options box clicked.

This is definitely a coding bug.  Adobe, please look into this !!!

[pvanCOLOR]

has this been fixed for anyone? -- my previews are still running too fast and the fix didn't work for me

[hunterh63283602]

It will likely never get fixed lol, it's been more than five years since Adobe started doing live RAM previewing instead of how RAM previews used to work so it will always be inconsistent for Windows users forever 

[jamesm46355552]

Glad to see i'm not going completly insane. I posted several times about this & didn't get responses from anyone. Ended up just going back to AE 2019 which solved the problem. However, no 2019 is behaving really weirdly. I have EXACTLY the same problems as your youtube video in AE 2020. top spec 2020 mbp. 

Completely ridiculous that Adobe havent bothered to address this, or bothered to even answer your post.