Dear Timi,
I've already tried so many times press the sync (in fact this is my first time to sync my diary in many years).
What it happened was I succeeded at the first time in my current cell phone (S20 ultra), but when I do the syncing at the new cell phone (Samsung S23 ultra), at the same time I updated my old Diarium from Google Play, and stupidly turned on automatic sync, the night mare happened, since then the syncing file in the Google Cloud collapsed.
Then I tried and tried the syncing process failed at the uploading 3000/32523.
After that I never succeeded. It all failed in the middle. Please kindly advise why and how. * I turned on the screen alive to always, and allowed running Diarium not battery optimization.