Kdenlive installations on Tumbleweed with KDE Plasma updated to Plasma 6 are missing the libmlt7-module-qt6 package which is required for the “Insert Title Clip” context menu item in the project bin. Install this package to fix the “Missing MLT Module: kdenlivetitle” error message at startup of Kdenlive and get the “Title Clip” menu item back.
The Kdenlive package should be fixed to include libmlt7-module-qt6 as a dependency.
Reporting it here isn’t going to accomplish much. You’d be better off going to build.opensuse.org and finding out who the maintainers are and e-mailing them, sending a message to the openSUSE-Factory mailing list, or potentially filing a bug against Kdenlive on the openSUSE bugzilla, so the maintainers are aware of the issue.