Indeed, it’s not ideal to see this behaviour and it is something I considered and tested for thoroughly before release so it’s a shame to see it affecting some people now.
Unfortunately I am unable to reproduce the problem so can’t begin to hypothesise what is causing it for you.
If a cause can be identified or a PR created to fix the issue I’d happily release an updated version to remove the annoyance. At the moment, given that I can’t reproduce the issue and there is a workaround (either click Cancel or just save whatever change is being automatically made) it’s not something I can spend a lot of time on myself.
I’ve made this post public in case anyone else can help shed light on the cause or potential fix.
I’ve been seeing this behavior too. In my case I see the KPRPC JSON being moved from “String fields” (Advanced tab) to “Plugin data” (Properties tab). Once I save the entry after this change, if I re-open the entry I’m no longer prompted to save it.
KeePass 2.57.1, definitely NOT a new database, KeePassRPC 2.0.2, couple of other plugins.
In some sense it might be nice to have a migration process that fixes all entries at once, but in practice I don’t know that it’s worth the development time. I can just save entries as I open them.