@OddDev Thanks for reporting; this has been fixed.
There is a small number of hashtags that trended early in the history of the "trending hashtags", and not since then, that had a misconfiguration applied to them some years ago.
Because Mastodon has still not improved the trending hashtags admin feature since then, there are no admin tools to manage hashtags that aren't trending, so the only way we can (quickly) resolve this scenario is once they are discovered and reported.