From Scribus 1.4.2 on, Scribus should find previously installed dictionaries while installing and be able to use them. With version 1.5.5 from the repository this doesn't seem to work. Although different dictionaries have been installed via LibreOffice, the option from the menu "Extras/Check Spelling" only shows "English (US)". Furthermore I can't find an option within Scribus to install additional dictionaries.
I use three installations on three computers, all of them Ubuntu 20.04. On one of them I can select from all installed dictionaries, on the two others there's only "English (US)".
Hunspell is not installed on any of the three.
apt-cache policy hunspell hunspell: Installed: (none)
What am I missing here?