There might be cases in which when trying to deploy SEs this fails but AVI does not release the license consumed by the SE immediately and might take around 30 minutes to 1 hour.
You can check from the CLI if AVI is consuming licenses for SEs that no longer exists using the following command:
show license ledger details
To force AVI to release the licenses immediately there is an API call that can be made using the browser:
If you're using on premise licenses:
https://[controller]/api/licensing/ledger/clear/reservation
If you're using cloud licenses:
https://[controller]/api/licensing/saas/reconcile/
The SEs in question needs to be already deleted from AVI and then the above commands should release the license that the SE consumed.