You could do that in one simulation with *BOUNDARY_SPC and *BOUNDARY_PRESCRIBED_MOTION using the BIRTH/DEATH options to activate and deactivate the BCs at specific times. Have look at the user manual for more information on these keywords:
If you are a commercial customer, please submit a service request on the Ansys Customer Portal:
We will be able to get your model and troubleshoot it. Ansys employees are not allowed to upload and download models in this forum.
Let me know how it goes.