Trouble shooting glitchy playback nothing has changed

All of a sudden Resolve is starting to play back the footage in my project very slow, skipping frames and delay.
I have not changed any settings. I am aware it could be a number of things, but where do I start to troubleshoot the issue.
I'm working with 4k BRAW footage, which normally plays back very smoothly on my system even when there are grades and effects on top. I normally only start to get playback issues when I denoise or sharpe, and this problem is happening with ungraded clips.

In the past I have often resolved such issues by duplicating the glitchy timeline. Its like magic - I am guessing new internal data-structures created on a timeline copy do not encounter those hidden bugs.

In the past I have often resolved such issues by duplicating the glitchy timeline. Its like magic - I am guessing new internal data-structures created on a timeline copy do not encounter those hidden bugs.

Worth a try, thanks. Although it is happening in other timelines in other projects too.

In the past I have often resolved such issues by duplicating the glitchy timeline. Its like magic - I am guessing new internal data-structures created on a timeline copy do not encounter those hidden bugs.

Worth a try, thanks. Although it is happening in other timelines in other projects too.

Curious - if it actually worked for you?