Indexing of new hashtags is broken when you're running ElasticSearch on your Mastodon server. https://github.com/mastodon/mastodon/issues/20230

Workaround:

Log into your server, then switch to the mastodon user:

su - mastodon

Test the indexing command by running

live/bin/tootctl search deploy --only tags

The command needs to be run regularly. Call

crontab -e

and add the following line for hourly indexing:

0 */1 * * * live/bin/tootctl search deploy --only tags

#MastoAdmin