It's been one year my mobile sim 1 not working

[ilahi]

I have Samsung galaxy note 20 Ultra dual sim 5g. Its been almost one year my mobile sim card slot 1 not working and I can see the message that sim card not allowed.

I contacted Samsung customer service and he told me to soft reset, then network reset, then turn on flight mode for 10 seconds then turn off but no result. 

My sim card slot 1 still not working. 

My mobile is still under warranty but why there is no solution? 

Samsung can replace my mobile phone but there should be solution. 

Thanks 

[Beth_S]

Have you tried the SIM card in a different phone or in the other slot @ilahi?

[ilahi]

Yes. Sim slot 2 working fine but sim slot 1 not working.

[Rūmøur]

This seems to be a common problem with their dual sim phones. Currently facing the same.proble with my s21 ultra. No signal/service on both sim slots after i did a security update. This sucks!!!

[CharlieCroker]

On a N20U and using dual sims with no issues. I just wish three and virgin sorted out esims