Glitchy syncronization between mobile app and web app

[pjfarr]

This has happened more than a few times now:

I mostly keep track of food on the Fitbit web app using Firefox. (I try to avoid using the mobile app as much as possible as it's too glitchy.) I had all the day's food entered, except for one item I forgot to log (for 69 cals). I'd already shut down my laptop, so I opened the mobile app to enter the last item. When it opened, none of the items I'd logged throughout the day were there. None. I refreshed a few times, no change. I entered the last item anyway and thought I'd figure it out in the morning.

Next morning, I open Fitbit web app in Firefox and all the items from the previous day are there, except for the one item I entered via mobile app the night before.

I opened the food log in Chrome and just the one item I entered via mobile app the night before was there. So, same food log for the same day, opened in 2 different browsers: Firefox showed everything entered via website but not the mobile app entry. Chrome had the mobile entry only, nothing else.The mobile app matched Chrome with just the one entry.

I synced the mobile app again, refreshed both browser windows, nothing changed.

My phone is a new Samsung Galaxy S21, the Fitbit mobile app and all browsers are up to date.

[LokeAa]

Are all browser plug-ins up to date? Any ad-blockers? If yes, fitbit.com is whitelisted?