I'm running 10.15.4. I've got Time Machine enabled and backing up to a 2Tb external drive with over 1Tb free (Mac OS Extended (Journaled)). It's been running for months.
But when I "Enter Time Machine" via the menu bar I can only view my backups from today and yesterday. Before that my "latest" backups is 5 months ago. I actually suspect that the visible backups from today/yesterday are local snapshots and not actually on my disk at all (as I can see these while the disk is disconnected).
When I open the actual disk I can see my
Backup.backupdb which contains visible hourly snapshots.
If I remove the disk from TM and try to re-add it, it now says there's no "latest" or "first" backup on the disk.
How can repair this?