Same problem here.
If I edit a note on multiple devices, it's the rule rather than the exception that a sync issue occurs (duplicates created). But even on one device, it happens several times a week for me, and I'm not a particularly heavy user - the other day, I suddenly had 3 identical copies of a note. This tends to happen most frequently right after the Evernote desktop app freezes randomly for 15-20 seconds, which it does rather frequently.
To me it does not appear to have anything to do with note size.
In a world where this stuff works smoothly in Google Docs, and mostly smoothly in Microsoft 365, I find it difficult to swallow the experience I've been having with Evernote since the "new" generation was released.