Notes Deleted after Connecting to WiFi

I have a lot of Notes on my iPhone. I must have messed up when using sync on iCloud and they all disappeared. I'm currently using iOS 14.x.

If I restore my phone from an older backup (with iOS 13.x), the Notes reappear under the iCloud folder heading, then immediately disappear. I think what is happening is that the phone restores the Notes, then restores the settings (which likely includes syncing Notes to iCloud), connects via WiFi to iCloud, and then the Notes are deleted (via a sync problem?).

So, I turned off my Wi-fi router, then did the same restore version. The Notes reappeared as before, but now remain there, and are all readable as normal. They are under the iCloud folder heading. I can leave Wi-fi turned off on my phone but if I turn it on, the Notes will disappear!

I would like to be able to sync these Notes on my iPhone with iCloud and my Macbooks without losing them on my iPhone. How can I do this? Thanks for any workable solution!!