This has been happening to me for a few weeks and, recently, it is replicable every day.
I used to use the Daily Note core plugin and, on suggestion from elsewhere on this discussion board, turned that off and went to Periodic Notes instead. That solved the problem until, like I said, recently.
If I initiate a daily (through Periodic Notes) on my (Windows) computer, subsequently opening the note on either my iPad or iPhone will generate a new, blank note from my template and erase what I had previously typed. I can do a File Recovery but only when back on the original computer.
The only way that this doesn’t happen is if I initiate the daily on an iOS device. The computer never overwrites from mobile.
The frustrating thing is that this happens ~50% of the time on iPhone but nearly 100% of the time (I just replicated before this post) on iPad.
I don’t have a lot of plugins operating and have gone through each one trying to figure out the problem but haven’t been able to do it.