Vivaldi Sync on my Android device fails to synchronize whenever I am connected to a Wi-Fi network. However, as soon as I switch to mobile data (LTE/5G), synchronization works immediately without any issues.

When connected to Wi-Fi, initiating sync changes the "Last synchronized" timestamp to 1 Jan 1970 01:00:00. Shortly after showing this date, a connection error message pops up.

Has anyone experienced a similar issue? Thanks for any help or suggestions.