Call forwarding keeps switching off

I have had issues with my call forwarding working since a few updates ago, but this latest update (15.3.1) has totally screwed it up. When I turn call forwarding on, it will turn itself off again, sometimes right in front of my eyes. I’ll toggle the switch to green and it’ll switch itself off again. When it “appears” green, when I try and enter the ‘forward to’ number, it doesn’t save. If I go out of the call forwarding section and back in again, the switch will be mysteriously turned off again.

I have tried turning call forwarding off, restarting my phone, turning it on again, restarting my phone, and it will have turned call forwarding off again on its own.

I have tried turning call forwarding on, restarting phone, and it’ll have turned itself off again.

I have tried doing the above with and without my wifi, mobile data and bluetooth turned on (note: I actually have to turn all 3 off to even get the call forwarding section of settings to even load).

Honestly so sick of this. For the price of these phones, they struggle to even work as phones.