The only issue i've ever had with sync on chromium browsers (specifically brave sync) is usually because gnome-keyring and kde wallet intercepts the sync which causes it to break
The only way i found to fix this is uninstall gnome-keyring (if using xfce or mate) or disable kde wallet (if using KDE)
You will need to start over on chrome and put it in a state where it thinks you just installed it and are first booting it up
i know with firefox browser this would usually be as easy as deleting the .mozilla file in your home directory unsure where chrome puts an equivalent file
Blame google for having such a crappy sync process
