Thanks for the post and the info you provided. I think we need a bit more info, though. Here is what we need from you: FAQ: What information should I provide when asking a question on this forum?
Hope we can help.
Which version of Premiere are you on? I've seen this happen a lot in the new CC 2019.
Also, does it play normal in the Program Monitor? Is the issue happening just in Timeline?
The issue is about the program monitor. The timeline is just fine, I can scroll it without problems but I won't see the playback in the monitor. I can also click the play button but it will stay the same triangle (when, while working, it turns into a square). I'm using CUDA but the problem is present also on mercury. I had the issue on cc 2018 but i updated to cc 2019 and everything was fine for a week or two and then the problem presented again. Do you have any suggestions?
You mentoned that it happens when you use GPU acceleration (both CUDA and Mercury).
What if you turn GPU acceleration off? Would hat work?