Call forwarding not working

[Voalizer]

Hi there, call forwarding has stopped working on my phone, it has been working fine for the last 7 months. I've tried to access it through the phones menu and by dialling the codes.

WiFi calling is turned off on my account. My phone is Xiaomi Mi9T running (Android 10 Miui 11)

If I use phone menu, I get message (Unexpected response from network)

If I use codes I get message (Connection problem or invalid MMI code (0) )

Does anyone have the same problem or can anyone help ?

Thanks

[MI5]

@Voalizer 

Has wifi calling always been turned off as those errors are usually connected to wifi calling?

Also, I'm not sure if connected or not, but there are some network issues today, particularly with customer accounts and the MyO2 app.

Finally, do you have a spend cap or have you changed tariff or anything that coincides with the issue?

[jonsie]

O2 are having some issues at the moment but unsure whether it would affect call forwarding.

Stupid quesstion but have you tried rebooting the phone @Voalizer