I recently updated the Super Admin to an existing user and reassigned their softphone number but the old super admin is still receiving calls to their call forward number (mobile/cell)?

Our 'default' super admin left the company and I updated the 'default' super admin to be me. I updated all the details to be mine and moved my existing softphone over from my old profile to the existing super admin profile. The problem I now have is that the former super admin, who had all calls forwarding to their mobile, is now receiving calls made to my softphone but with my softphone as the caller ID. The calls are simultaneous ring as I'm getting them too. I've checked all the settings and can't find their number listed anywhere for me to remove or update it.