Maybe just rename the original administrator account and use it, instead of removing it and using another admin account.
Other than that you might be able to edit manually the file administrators.json, while the service is stopped, to move the:
"is_primary_admin": true
flag from the old account to the new one.
Be sure to backup the file first in case something goes wrong...
Sébastien Riccio
System & Network Admin
https://swisscenter.com