Quack,Just a message to say that redmine 4.0.7 was uploaded to backports with many fixes. ruby-i18n 1.5.3-1+deb10u1 is coming in the next point release fix a needed fix, thanks to Daniel.
So we should soon be in a good state here.Do not hesitate to contact us if any problem. Since we're the same ones doing the usual redmine packaging you can also use the BTS for this, that would be easier to follow individual problems.
Regards. \_o< -- Marc Dequènes