iPhone xs cellular lte/4g signal drop

When just my primary sim is active signals comes easy that too on 3g data settings but when i switch it to 4g(lte) volte signal keeps going and coming after 5-7 minswhen i turn on both my physical and esim both of my networks run away as my secondary sim just works on 4g it shows one bar maximum but it’s not reachable when called on this number I think their is something with 4g of my phone itself

help me out I’ve been to apple authorised service centre in my city the front desk staff diagnosed my phone and not showing any abnormalities on their system and said if i have this network related problem I should get it replaced for 56 thousand INR(out of warranty). 😓 how come it’s not repairable if something is wrong with the hardware as my phone has never dropped or have a single scratch.

When just my primary sim is active signals comes easy that too on 3g data settings but when i switch it to 4g(lte) volte signal keeps going and coming after 5-7 minswhen i turn on both my physical and esim both of my networks run away as my secondary sim just works on 4g it shows one bar maximum but it’s not reachable when called on this number I think their is something with 4g of my phone itself

help me out I’ve been to apple authorised service centre in my city the front desk staff diagnosed my phone and not showing any abnormalities on their system and said if i have this network related problem I should get it replaced for 56 thousand INR(out of warranty). 😓 how come it’s not repairable if something is wrong with the hardware as my phone has never dropped or have a single scratch.