Keypad not working during phone calls

iPhone 15 ios 17.5.1

During calls when recordings call for using keypad numbers, it often does not work at all.

I have restarted phone to no avail.

I see this has been an issue since at least #11. There are a lot of other posts. I did not know how to get to the most recent suggestions to fix it.

Have tried some methods found with google search but mainly they say reboot. Which doesn't work.

I confess I am not happy with the many frustrations of this iphone.