Not exactly what you are looking for, but you can search for +@helpers +images which should get you all postings to the forum that deal where the word images was used in, but not only this that are tagged with the word.

@Tobias hmmm, now I'm trying to talk up this feature on a post about how mastodon search sucks https://mastodon.social/@lohang/110209507993705568 but now when I search for something like +@fu +hockey, which i post about a lot or +@fu +birthday which i just posted about today but +@lohang@mastodon.social +search finds a bunch of posts he posted in that mention search. Is this something screwy on a recent update, or what? @Libranet Support @Steffen K9 🐰

@Ji Fu @Steffen K9 🐰 @Tobias can you try with the complete handle @fu@libranet.de?

I would need to look this up but I have something in mind that there is a minimum number of characters in MariaDB's full text indices. So, maybe 'fu' ist simply too short.

...my memory was correct.

innodb_ft_min_token_size

Description: Minimum length of words stored in an InnoDB FULLTEXT index.

Default Value: 3

@Steffen K9 🐰 @utzer [Friendica] @Tobias hmmm I recall it working great last week when I first read this thread as I found the one I had been looking for, and now if I search for [+@fu@libranet.de +birthday] (also tried hockey, tor and onion) I also get no results