I see this remark of you. I assume that you put it there in case it might be important. But in that case it would be nice if you added how you did that upgrade. Others will not be able to point to a flaw in what you did when they do not know.
I never would leave any non-standard repos (including Packman) enabled during such an upgrade. The --allow-vendor-change would then switch everything back to OSS. And enabling and zypper dup --from [packman] would then change to Packman what is needed (and that could differ from those of the old openSUSE version, but the switching back and forth would handle that).
And again, I never looked at “lists of codecs”. Since more the 10 years I simply do the switch. Period.
That is NOT the switch to Packman. It will only update your present installed packages when newer versions are available for them from the same vendor. No vendor change done.
See post #7 above!
(where [packman] is to be replaced by the Alias, Name or Number of your Packman repository).
Or
YaST > Software > Software Management; then from the View meny > Repositories; select the Packman repo; at right above the list you see something like Switch system packages to …; click it.
Both are documented many times in stickies about Multi-Media and other threads.
In any case, once you have switched to Packman, as long as you do not use commands that allow a vendor switch, you are fine.
As said, zypper up (or zypper patch)will NOT change vendor and thus any updates will come from the same vendor as the original package: OSS packages from OSS (Update repo) and Packman packages from the Packman repo. All you you would wish I assume. Easy going.
And when ever you want to install something new (zypper in or using YaST > Software > Software Management) and that package can be found on more then one repository, then the package from the repo with the highest priority will be installed. After that vendor stickiness will restrict updates yo that vendor’s newer version. All what you most probably want.
I hope that, having it explained several times, this helps.