Upstream translations imports to cosmic might be missing (due to translations sharing launchpad option)
It's the not the first time/cycle that option creates issue, but when
"sharing with an upstream vcs" is being used then the translations from
the package uploads are not being imported.
In theory the vcs sharing is a nice idea, but in practice most of the
GNOME upstream imports on launchpad are outdated or buggy and as a
result the translations don't get updates.
Unsure how that option get turned on again but it was activate on most
desktop/GNOME components (if someone did that please don't do it
again!). I did go through the main applications/desktop component, unset
the option and did no change uploads to cosmic to get the source
translations imported, I didn't do rebuilds for every package though
since a good part looked like they had uptodate enough translations. If
you have a project that you think would benefit from an new import
though, feel free to respond to this email.