device can't verify Server Identity

[Spica]

Hello. I don't remember from when but at least from the beginning of this year, my iPhone said "Cannot Verify Server Identity" and hard to get internet in some area. Not for all area but some of the area, I got this difficulty. 

Even I updated my iPhone from 11 to 13 but still this continues.

Is this related to my SIM issue or anything?  

I always reboot my phone but at that area, it didn't work.

If you know the root cause and how to do, please let me know.

Thank you.

[DeanKevin64]

Not sure how much help you will get with this particular issue here in this community, there is not much traffic. I did do a quick Google search and it appears this could be an issue with your phone. You might want to try the Apple support community. 

I tried to link an article from my Google search but this community considers the 9 numbers that are in the link as a bad word for some odd reason. 

Here is the wording I used, cannot verify server identity iPhone 13, scroll down to an article from December 18th, 2023, there are a number of links for solutions see if one of them will help fix your issues or even one of the other article.

[Spica · Accepted solution]

Thank you very much. I will search your wording to find the solutions. Thank you again!

[upstate-SC]

Are you using eSim or physical sim?

[Spica]

My iPhone 13 is not eSIM. Thank you for helping.

[upstate-SC]

As the previous commenter says the issue could be Apple's Mail app related. 

[Spica]

Thank you for trying to help me. I really appreciate it.