AFAIK in place upgrades from one major version to the next aren’t supported with Rocky but it looks like that it is possible. Looking at those modules it seems like they are el8 specific modules so you can probably just disable them as shown here, read the part under “Step 7: Post -installation steps”.
Red Hat did adopt the dnf modules, “streams”, in el8 and went totally overboard. Almost everything is a stream in el8. With el9 they are much more conservative. The modules do pose issues even within el8 (e.g. for third-party repos), let alone in unsupported conversions.
you may find you’ll have to do that for each of the modules you have issues with since they are modules listed for Rocky 8. You’ll notice in my disable command, httpd also features there. My module disable command would differ to yours since you don’t have those in use on your system, or at least not all of them just some of them. So adapt the command to fix the modules you have issues with.
Thank for all the insides. In case it is helpful for others, that is where I stand and what I did so far:
Server seems to be working fine; it still does it job as modem/router, web server, cups server and media server (emby) .
Modules warning; I moved all files from /etc/dnf/modules.d into another directory to see what happens. I have not seen any anomily nor error and error messages when running dnf update do not apepar anymore.
I had to install ddclient and certbot again. They were dropped during the upgrade.
There were ‘el8’ prgorams left which I all deleted and reinstalled if available with the exception of the list, as their deletion would also undelete ‘el9’ prgormas and I am not sure what harm it will do.