Sequencer attach track stopped working with control rigs.

Guys, has anyone experienced an issue in Sequencer where the ‘track->attach’ function suddenly stopped working for control rig models? Everything was working fine until something happened. All existing bindings still work with that control rig, but I can’t attach new meshes to it. As an example - I’m trying to animate an excavator that is picking up and changing different attachments. I’ve reinstalled Unreal and updated to the latest version, but it has somehow stopped working for all projects, not just the specific one. Thank you.