Hi Andrés,
yes, that is what I mean. Now, what I think happened is the following:
You ran "apt upgrade" which upgraded a bunch of packages. However, a
number of packages were held back because upgrading them required the
removal of some other packages (e.g. kwin merged some binary packages,
nothing strange about this). You then ended up with a hybrid of Plasma
5.25 and 5.26 which lead to some weird behaviour such as certain
plasmoids not working correctly.
The fix was to upgrade everything while allowing the removal of certain
packages which could've been done with "apt full-upgrade" as well.
Unfortunately, there is no way around this when packages need to be
removed.
I'm inclined to close this bug unless you object because there isn't too
much we can do here. Migrating Plasma from unstable to testing has
always been challenging.
--
Med vänliga hälsningar
Patrick Franz