Jpeg in the timeline

I have some Jpegs in the timeline and they are running very bad. They are stuttering and the very short ones with 10 frames, will not displayed at all. Tiff files are a little better, but not good. Okay, because I want to zoom in, the files are large, around 15 Mb, but a 10 seconds 4K are larger and have still to be decoded.
What is wrong there? Has anybody similar experiences?

JPGs are highly compressed, so I would bet they're relatively CPU-intensive to decode and playback. TIFFs and PNGs are not, so I generally go with those when I have to use still frames. They generally work pretty well on my system.

If your system has trouble with these still formats, then one possible workaround would be to export the material as a flattened 4K DNxHR file and bring that in and do the repos on that.

Tiffs are better, but not good. So I will try the way with DNxHR
Thanks Benn