Cellular Issue Detected iPhone 13 Pro Max

My phone keeps saying there's "Cellular Issue Detected"

I've already done all of the following:

1. I have updated my phone to the latest IOS
2. I went to my carrier and requested for a new sim
3. I've backed up my phone
4. I've reset the network settings (multiple times I might add)
5. I've hard reset my phone
6. I've contacted 3 Apple support via chat in different dates
7. I got to talk on the phone to the Apple support team from Singapore
8. I went to the Apple service center in my area and told them they can run a diagnostic but if they find that theres a problem with the hardware, they cannot fix it. The only solution is to buy a new phone.
9. I've already run a diagnostic test with Apple support and they found everything to be in good shape
10. The cellular issue started happening only days AFTER my warranty expired, so this is a fairly new phone.

It's quite unfair to buy a new phone and potentially have the same problem again. What's the guarantee that IF I buy a new phone, I wont encounter problems like this anymore? It's like a guessing game and a game of change that when I buy a phone, I just hope and pray that the unit given to me wont have issues in the long run. I'm very much open to paying for services to fix the issue but the only option they gave me was to buy a new phone and for a phone that literally just turned 1 year old, I am not willing to spend crazy amount of money again. Does Apple really have NO WAY of fixing the hardware for cellular data issues??