iPhone 11 is not 5g so as of December my next work has had problems
Do I need to change my service provider because my service on your network has been very poor since 12/22
iPhone 11, iOS 15
Question marked as
Only if you have an iPhone 12 model or later with a 5G connection you can use over the 5G network.
Check if your carrier supports 5G, see -> Use 5G with your iPhone -> Use 5G with your iPhone - Apple Support
If your carrier supports 4G, it will also work with other types of iPhone.
(here SE 2nd gen - 4G)
Do I need to change my service provider
Try this -> remove and reinsert the SIM card.
If it doesn't help contact your carrier, maybe the SIM card is damaged, ask for a replaced (new) card. Normally it is free.
Ask also to check if the SIM tray is bent, as even a tiny misalignment can cause the SIM card to not fully connect with the internal contacts in your iPhone.
If it doesn't help, see these Apple articles below:
If you see No Service, Searching, or SOS on your iPhone or iPad
If you see No Service, Searching, or SOS on your iPhone or iPad - Apple Support
Manually update your carrier settings on your iPhone or iPad
Manually update your carrier settings on your iPhone or iPad - Apple Support
Update your network provider settings manually on your iPhone or iPad
Update your network provider settings manually on your iPhone or iPad – Apple Support (UK)
If they are On, turn Off Hotspot & VPN.