Here's the bug description (I copied a post by alekseyg79178945 in the Adobe Support Community - he explains it very well):

"The current situation is as follows: I have a Premier project in which there are several dynamic links to 3 different AE projects. The first type of links to 3D animation, the second type of links to text animation, and the third type of links to 3D animation in AE. Until the April update, everything worked fine.
After the April update in Premiere, the project links are loaded from only one AE file. The rest of the AE files do not load, even if I forcibly used Link Media.
After several attempts to figure out the situation and find out what the problem is, I realized the following:
If Premiere Project have Dynamic Links to more than one AE project, it will only load the link to the project that is curently loaded in AE, and will completely lose touch with other projects."

Trying to relink the offline AE projects you will only get an "unknown error occured".

I'm having the exact same problem. Dynamic link basically is unusable this way. Please, please, please take a look at this bug!!

TLDR:
Speed ramps cause massive playback issues on non-rendered clips for interpreted footage.

the problem is with interpreted footage + cuda playback

(on windows, cuda playback on)

4k H.264 OR quicktime cineform footage 29.97, interpreted to 25. 
On a 1080 timeline.

Add a speed ramp to footage (any amount shows the bug but the higher it is the more obvious it is)  playback is borked. At the start of the ramp the footage jumps around in time.

This does not happen on non-interpreted footage, it does not happen when you use a 29.97 clip on a 25 fps timeline.

Absolutely awful workaround: create new sequence from clip, set their speed to 83.41675008341675‬%,

Absolutely awful workaround 2: render and replace interpreted footage in new sequences.

Absolutely awful workaround 3: switch off cuda playback.

Aren't versions supposed to improve as there are new updates? This is 14.5! Not 14.0.

I get crashes when trying to attach proxies. (I created my own h.265 proxies for 120p footage in handbrake because when I try to create 120p proxies in Premiere it changes the frame rate to 60p making the proxies unusable..) I can attach 1 at a time and it works perfect, however if I try to do all of the 168 clips, it says "Not Responding" for several hours and if I click on anywhere on Premiere while it says the message it crashes. Same thing happens if I try to do more than 1...?!! It seems to get stuck on 'Locating Media'. Then goes to not responding. The proxies are literally in the same assets folder.

This program is so buggy.. Using adjustment layers with Transform/Wave Warp effect for example just doesn't work sometimes, either the transform effect won't do anything when adjusted, or the screen will turn black when using Wave Warp.

Or when working with scale/transform keyframes in Effect Controls, sometimes the left and rights just disappear and I have to move the panel window to get them back..

If I open a new project, my windows layout moves the Effects panel window to a tab in the Projects panel window for some reason, and I have to move it to where I actually saved my workspace layout...

Playback of H.265 is super buggy, it causes weird blocky noise. Davinci resolve works perfect..

Also, Sync settings just doesn't work; Hasn't worked for several versions. It says 'Sync Failed' when trying to upload local settings. (Trying to save all of the custom settings that I use daily incase I have to ever reinstall, which is the point of cloud settings right? Unfortunately it just doesn't work.....)

Why does After Effects RARELY crash year after year and same with Photoshop, but Premiere has always been TERRIBLE with stability? Isn't the Premiere team tired of having customers complain about stability? I'm honesty just sick of filling out these forms for the SAME thing to have the following release with a slightly different effect or feature. PLEASE JUST MAKE A STABLE EXPERIENCE!! STOP RELEASING VERSIONS THAT HAVE BUGS. FULLY TEST IT BEFORE RELEASE WITH A TEAM OF EDITORS WORKING ON BIG PROJECTS ON DIFFERENT SYSTEMS.

All of your paying customers don't have time to be troubleshooting and reporting back, filling out these feedback forms; we should be working on client projects.

PLEASEEEE......!!!

Premiere Pro 2020 is the most unstable release that our company has every experienced.
It constantly freezes and crashes whilst performing the most basic of tasks for an NLE. Highlights include:
- Opening a file in the source monitor
- Adding a keyframe to an audio clip or track
- Importing files
- Adding or deleting tracks
- Playback
- Any form of editing in the sequence
- Adding text

The list goes on. And on.

So far, reseting Workspace, reseting preferences, reinstalling the software... Etc... None of this works or helps.

This is happening across many different types of source media (ProRes / MXF / Wav etc...).

It's happening whist connected via 10GbE fibre to an SNS EVO NAS. Whilst connected to a TB2 hard drive, USB 3 hard drive...

It continues to happen when I disconnect any peripherals.

And the same issue is happening in all three of our edit suites.

This is, without a doubt, the most unstable version of Premiere Pro that I've worked with throughout my career.

Premiere is fast becoming one of the most expensive NLE systems to run, due to actual subscription cost and time wasted troubleshooting constant issues. And to make matters worst, Adobe has the weakest customer support ecosystem of them all.

The Adobe user base deserves more than this.

Running (or al least trying to run) Premiere Pro 14.6.0 (Build 51)

Mac OS Catalina V 10.15.7

Mac Pro (Late 2013)
Processor: 2.7 GHz 12-Core Intel Xeon E5
Memory: 64 GB 1866 MHz DDR3
Graphics: AMD FirePro D700 6 GB