Can't search for communities in Mastodon

Hi!

I just created a Lemmy server at https://upvote.au/ for my personal use. I created a test community with a test post, but searching for it in Mastodon doesn't work. I tried searching for both @[email protected] and @[email protected]. I see the requests in the Nginx log:

172.19.0.5 - - [13/Jun/2023:22:57:06 -0700] "GET /.well-known/webfinger?resource=acct:[email protected] HTTP/1.1" 200 312 "-" "http.rb/5.1.1 (Mastodon/4.1.2; +https://toot.d.sb/)"
172.19.0.5 - - [13/Jun/2023:22:57:06 -0700] "GET /c/test HTTP/1.1" 200 10033 "-" "http.rb/5.1.1 (Mastodon/4.1.2; +https://toot.d.sb/)"

However, no results appear in Mastodon.

Any ideas?