Blank red dot on voicemail since ios16 update
as always I update to the newest iOS as soon as possible, but this time I have now got a blank red dot on my voicemail, there is no messages stored, I've tried airplane mode, I've restarted the device, I've turned badges off and restarted then turned back on, I can't do anything with settings > phone > voicemail password, it says unavailable.
any help appreciated.
iPhone 13 Pro, iOS 16