iPhone 14 keypad is not being recognized by ivr telephone prompts.

my iPhone 14 keypad is not recognized by telephone prompts on customer service lines. i had an iPhone before and did not have this issue. When I enter in my selected numbers the phone is beeping as through the response is being entered, but then it says the number is incorrect and I try again 3 times and then the call is disconnected. Initially I had to take off WIFI and it worked for a period of time, now that doesnt even work. I can use earlier model iphones which I have had to resort to and they work no issues at all. Its frustrating when I have to deal with government departments everyday and have to keep borrowing phones to do so. How do I fix this?