I have an unlocked Honor 6X and I am not receiving text from iphone users, how can I fix this?

[Android Central Question]

I just bought the phone from Amazon.
I have T-mobile as a service provider.
The phone is UNLOCKED.
I only have 1 sim card inserted.
I tried restarting it. (should I factory reset it?)

I have gotten a few text FROM iPhones but AFTER an update to the phone system I noticed that I stopped getting text from iPhones.

 

[KeoW950]

I figured out the problem.

I had previously been using an Apple device and apparently when I switched the SIM card to the 6X, it was still connected to my iMessage.

So to resolve the problem I had to "erase" the iPhone.

 

[ksharifi294]

I have exactly this problem. T-Mobile, receiving some iPhone messages but not others, etc. Only difference perhaps is that my last phone (iPhone 5) was stolen so I cannot access it.
But primarily: what do you mean "erase" the iPhone? I'd love to know.