Did I understand you correctly that you upgraded your customised modules in the Management Console?
Unfortunately, it is not possible to downgrade them to a lower version in that case.
However, any new modules that you create will take on the version of the licence that is attached to your Management Console. If a version 11 licence is activated on your account, any modules that you create will be modules in version 11.
As the Management Console should only prompt you to upgrade your modules once a licence for a higher version is activated, you may also want to check whether your company purchased a licence update and is already using TeamViewer 13 now. In that case, there would of course be no need to delete and re-create your modules.
I hope this information helps. Should you have any other questions, feel free to let me know.
All the best,
Did my reply answer your question? Accept it as a solution to help others, Thanks!