problem entering the code of the client's phone number, that is, the country code

problem entering the code of the client's phone number, that is, the country code, whenever they unden in a country it automatically takes them out, it doesn't let them put it in, it seems like it was a bug, Below I am going to show how it appears for me and my visitors to my website, the flag of the country does not appear, or anything, and when you click on an option, it pulls you back and takes you out of the form, this It happens on the cell phone, I tried it on the PC and it seems to work fine, but the biggest source of traffic on my page is on the cell phone and that is a problem