The other day my dashboard filters were working as they should. It was providing a list of all available options. Today, it is no longer doing so.
Which version of Metabase? Which database are you querying?
Have you (or someone else) made any changes to the dashboard or questions on that dashboard?
There’s a known issue, where having filters connected to different questions, which uses different tables will not show the dropdown.
But if you didn’t change anything, then the only thing I can think of would be the sync/scan done every night failed for some reason, but you would have to look at the log.