This bug has happened a couple of times on me, but it isn't consistently reproducible. However I managed to catch a screenshot of the last time it happened.
I had been working in my Library for a while, filtering it, and tagging things. I had it in Browse mode, grid view, with the Info panel open
I typed nbd into the Library find box.
New Bible Dictionary came up and this is what its info panel looked like:

Note there is no add tag. In fact, the entire second line of tag info is missing. Here's what it looks like when the bug isn't reproducing, which is more often than not:

I have not changed the tagging on this resource between when the bug has turned up and when it hasn't. It seems utterly random.