Notes APP on iPhone does not sync gmail notes or just sync some of them, sometimes content of the notes might disappear

Hi all, is there anyone who can help me out this frustrating situation?

I use the Notes app on iphone but the default account is my gmail account. As we all know that the Notes app from time to time cause trouble. About 2 weeks ago I searched for a note. The content does come up but when I click on that note entry there was nothing there. It always happened in the past if I didn't switch to the main folder list before leaving the Notes app (even just move to another app temporary). This time it happened again. The notes itself definitely still exists. I checked my gmail. so, I toggled off Notes option from Settings-Notes-Accounts-Gmail-Note, and then switched it back on. However, it was just until yesterday that I found 0 notes appear in the Notes app. I checked my gmail again. All good. I checked the Notes app on my Mac. All good. I then deleted the gmail account and re-added it. The funny thing is this type when the account was added, Notes tab was by default turned off. I turned it on when saving the account. However, no notes came back. I did this many times after this. There was once, it copied over 250 notes, and another time it synced 8 notes. I can create notes and the new notes entry will be synced with gmail.

Here are the additional things I tried.

1. deleted the notes app and reinstalled
2. copied notes into icloud account (on my mac) and then copied them back to the gmail account on my mac. Gmail and my mac work with each other well but the notes app on my iphone does not work.
3. upgraded my iphone 14promax to ios16.3
4. setup the default notes account to icloud and then back to gmail
5. deleted and re-added the gmail account many many times (each time the notes toggle was off by default for some reasons)
6. enabled another gmail account and copied some notes over (same **** happened, only 36 notes were copied over and then it stopped). It looks to me that there is a problem between the notes app and gmail. they don't talk to each other or it's a one-way street.
7. reset network settings
8. changed mail push settings, tried options every 15 mins and automatically, switched to manual and then back to fetch
9. I have another old iphone, that phone connects with gmail notes well

Anyone has any solution?