Do you know which ones?
I just deactivated all my plugins and the problem is still there:
as soon as I make even a small modification in a note, the sync starts and Joplin lags, even sends my cursor back to the top of the note 
Ah, I just tried what I was dreading: setting the synchronization target to none. I was afraid that by restarting WebDAV afterwards, the sync would have to start from scratch, but no 
, and as long as I'm on none, Joplin works fine! And all this without needing to restart Joplin.
This workaround lets me use Joplin again
But now I have to find the culprit of this slowdown.
I wonder if this problem comes from the amount of notes and tags I have and/or the fact that I use WebDAV as a sync target and/or because my PC is too slow?
I just did a test of my SSD, even if there is better, it seems correct to me:![image|466x257]
Also, here is what @laurent told me on my other topic:
Downloading the list probably doesn't affect the app much but parsing this giant XML file probably does. So maybe that's the slow down you were experiencing - to make it happen less often you can increase the sync interval.