This is a tracking bug for Change: Disable Vendor Change by Default
For more details, see: https://fedoraproject.org/wiki/Changes/DisableVendorChangeByDefault

Change the default configuration of DNF5/libdnf5 by setting allow_vendor_change=False via the distribution defaults file /usr/share/dnf5/libdnf.conf.d/20-fedora-defaults.conf. This prevents libdnf5 from automatically replacing an installed package from one vendor with a package from another vendor during any transaction (such as upgrades, downgrades, or dependency resolution), unless explicitly requested by the user or allowed by VendorChangeManager rules.

If you encounter a bug related to this Change, please do not comment here. Instead create a new bug and set it to block this bug.