(Warning: WordPress newbie ahead...)
I have a WP site with a bunch of posts, many of which have tags associated with them. However, clicks on links to such tags -- https://example.com/tag/sample-tag) -- don't produce the pages I would expect -- a collection of teasers for posts with that tag. I just get the "nothing" page -- "Nothing Found / It seems we can’t find what you’re looking for. Perhaps searching can help".
I've dug through the database, and it looks like the tags are set up correctly -- proper cross-pointing entries in wp_terms, wp_term_relationships, etc, and the tags from the site show up in the standard WP Tags Cloud widget. I've checked the site logs, and the requests to /tag/sample-tag or whatever are returning a 200 status code, so the underlying mechanism seems to be ok -- it's just not producing the matching pages. Down in the Permalink settings, I've tried setting the optional "tag base" field to "tag" or to nothing, but neither works. I've also tried switching from my custom theme to twentynineteen, but I get the same behavior there.
So: Any ideas? Am I misinterpreting how these links are supposed to work? Anything else? Thanks!