Mastodon's core has just had a new update released, v4.1.0

You can see which version your server is on by looking at the bottom of your server's website.

Highlights include:

:mastodon: Lists of hashtags you follow (go to your profile, click ︙ & Followed Hashtags)

:mastodon: Hashtag search suggestion bug fixed

:mastodon: Support for importing admin domain block lists, this will greatly help your admin keep your server safe.

...and lots of other stuff (https://github.com/mastodon/mastodon/releases/tag/v4.1.0).