Very slow playback after updating to 18 Beta 3 and revert.

Hello, so I decided to test out the new Resolve Beta 18.3. I had been using 17.4.6. All was great with 17.4.6 and then I uninstalled it and upgraded to 18 after backing up my database. I then installed 18 and when I did, all my footage on the source and record side were jerkyy and the whole program is reacting very very slowly. I am using all ssds with separate drives for cache, and such. I am only using a 1080 23.976 timeline with ProRes 422 footage. that was fine with no color effects or anything else. It was horrible. I Checked all my settings and they were fine, nothing taxing my system. Previously I could playback with no render or proxy with color effects and more with no issues. Anyhow I went back to 17.4.6 and now It is acting the same way as the 18 was. Very very stodgy and bad.
Does anyone know how I might be able to fix this.. any preferences or hidden files I can delete?
I have a 2019 MacBook Pro 15" 8 core i9 32gb ram and a Radeon 560 internal and an external RX580 GPU as well. Until this upgrade I had no problem at all and it was as smooth as silk even with Alexa log footage.
Any ideas?

Maybe check which of the GPU's is in use?

I also have a jerky handling of the program. It is as if my pc laptop needs to stop to think every five seconds. Playback is going from 25fps to maybe 7fps and then trying to catch up with more than 30fps. Moving the cursor is jerky too. I'm considering reinstalling Windows but to do that I need to find my license for the studio version.
Any help appreciated.

im having a similar issue with playback. and this problem has been an issue since beta 2 was released. it will just stop playing back. I thought it was a b-raw issue but once the clip just freezes it freezes every clip in that project til I restart. its actually completely unusable.

I'm having the exact same issue. I've kept all the same settings I've had for the last six months. It's as if my system is suddenly inadequate for even basic tasks.

check if the GPU is correctly selected and it is not in AUTO but appropriate manual selection: CUDA for Nvidia and whatever selection you need for the AMD.

also check in the user preference if you have the performance on/off and which other selections are applicable.

Sadly its NO to all your solutions. I went thru all my preferences and GPU settings and none of that has any effect. It is a bug of some kind. After further investigation, after backgrading to 17.4.6 and having the same issues as mentioned. I realized the whole program was reacting terribly and even clicking on bin clips was having the delay and slow issue. I solved it by taking the Blackmagic Design folder from the User Library folder of my backup hard drive and replacing it over what 18 had installe. Now 17.4.6 works fine again. I am now going to Try re upgrading to 18 beta 3 and then putting that folder from 17.4.6 in from my old prefs and see if that fixes it. Will report.

Same issue here. Been having terrible playback for the last 2 patches. Strange stuff all around. Some days it will work perfectly fine, but most of the time, resolve is extremely slow.

Nothing is bottlenecking in the task manager.

It says resolve is playing at 25 frames, and has a green dot next to the frames played, but it's actually really laggy. Even using proxies without any grades is slow.