I think/guess that the keyboard the paypal app is opening is actually the phone number keyboard.
/usr/share/maliit/plugins/com/jolla/PhoneNumberLayoutPortrait.qml
which also has that “*p”
I did not try changing that layout to add the “dot”, which might well work around the problem.
So either the paypal app is indeed requesting a phone keyboard, or it maybe wants to have another one which is incorrectly mapped to phone.