Only briefly for fun (and OCaml too but very long ago). F# does seem like a language I feel I could really like, though.
I’ve tinkered a little in Gleam and Elixir too. Elixir was incredibly enjoyable, and Gleam is a wonderful language that I wish I could work with more, but I don’t really have a use case for it and nobody will pay me to write it…
Back in 2009, I also spent a few months playing with Factor (before switching to Clojure because despite Clojure being niche, Factor was even more so). It was an interesting and somewhat mind bending experience.