Hi Carl,
In …/nextcloud/config/config.php you can put
‘force_language’ => ‘nl’,
‘force_locale’ => ‘nl_NL’,
I just took these lines out and set the language manually, but OnlyOffice still shows up in English.
Edit: To further clarify, my latest endeavor is a clean installed Ubuntu 22.04 VM, the other runs Ubuntu 20.04. Nextcloud runs on Ubuntu 20.04 as well.
The OS language is English for all.