I was preflighting a pdf for accessibility, and noticed a few pieces of text that had been mistakenly tagged as Artifact. I selected these in "Content", Right-click and "Remove Artifact". But now I can't tag these at all. They're not to be found in the tag panel or the read order panel, but they're visible and still there in the Content panel -. I think this is a bug. I tried using "Find" but the content was not found.