The fix will only affect newly created sequences
When an actor is attached by the root to a bone of a skeletal mesh through the use of the "AttachToComponent" function in code, it will not follow animations when being recorded by the Sequencer Recorder.
This does not occur if the Mesh is the root of the actor, therefore in the repro case above, a Scene component is set as the root. It also does not occur if the entire process is done through blueprints. C++ is required to reproduce this.
Additional steps to test with new sequence:
Head over to the existingAnswerHub thread and let us know what's up.