@blogdiva @afreytes ActivityPub objects have a separate field for hashtags (categories), just like they do for “destination” (To/Cc fields). Mastodon manages these in the post content, but not all platforms do. So it's possible that the metadata is present, but Mastodon doesn't show it. Looking at the original ActivityPub object would, though. If you still have an example around it would be interesting to check.
