number unknown

[phonebroke]

Hi my phone has lost its number  it's a as21 under settings it says unknown  and  should say it's number has my phone been swapped or hacked ? How do I put it right  

[DUMITRU79]

Is your mobile signal very poor ?
Are you using a SIM card from Lyca / GiffGaff / Lebara ?

[phonebroke]

signal 2 of 4 sim Tesco and there is a triangle with arrows in it what's new phone 2 months old due to qr reader for covid

[DUMITRU79]

Can you make a screenshot and post it ( of the home screen) , please ?

[DUMITRU79]

Is it something like this ?

[DUMITRU79]

If that's the case , ilt means "data saver" is on. To deactivate, go to :
Settings -> Connections -> Data usage -> Data saver and turn it off

[phonebroke]

do you no why under about phone it says phone number unknown???

[DUMITRU79]

Does your phone has a custom ROM ( firmware) ?