When you say you "inherited the package" do you mean the Fedora package (downstream) of libpwquality (upstream) ? If not, please clarify.

And you mentioned recently fixed items. Where are these fixes: patches to a downstream package, fixes in a fork of the upstream repository, ... ?

The (translatable) strings in Weblate are extracted from a source code repository, which in this case seems to be the libpwquality GitHub repository you mentioned (notice the "Translations update from Weblate" pull request automatically generated by weblate bot user). If your fixes have any impact in translation strings, and you want them to be available for the translators to translate it, then yes, they should be submitted to the upstream.

I've inherited the downstream package in Red Hat (and Fedora).
I'm speaking about the patches currently in Weblat. I've fetched them and added to the RHEL9 package. So I wonder should I communicate with upstream to push the strings from Weblat to the upstream GitHub

So the patches you mentioned are the new translations contributed which are only in Weblate and not in upstream repository at the moment, right?

If that's the case, don't worry. Weblate automatically opens a pull request in the upstream repository and keeps it up-to-date with any contribution, so the upstream merges it when convenient for them.

See https://github.com/libpwquality/libpwquality/pull/54 by weblate "user" and notice how there are some "force-pushes" -- it's all automatic

Obviously, if it is taking too long to have it merged (e.g. there was new releases and the translation from Weblate was not merged), one can ping the dev/maintainer asking to merge it.

Many thanks! It fully answers my question.

You're welcome, and thanks for caring about localization. For sure the l10n contributors appreciate it.