Transparent Video New Behaviour

Transparent Video Clips suddenly started behaving differently today in PPro 2023. I used to be able to duplicate and use duplicates in a timeline and each clip used to be a separate distinct clip with it's own name and characteristics (which did not appear in a project - like titles do not appear). Now, suddenly all have started behaving as if they are are instances of a master clip - change one name and it renames all instances.

Where can I get information on when this was changed and how?

R.