Writing this down in case anyone else has this problem.
First noticed when using writer, LibreOffice didn’t have a dictionary and couldn’t spell check.
I tried changing document language, installing adons, reinstalling libreoffice but all to no effect, Libreoffice couldn’t spell check.
Finally I uninstalled the cachy version and used Shelly to install the flatpak version. This fixed the issue entirely. Not sure on the original cause though.
I have hunspell installed. Since I didn’t install it myself I’m assuming it was there beforehand. I’ll go ahead and reinstall cachy libreoffice and add a few from that page.