Thanks for moving that to the next level. I think with the findings so far the bug seems very paypal app specific, or could be about a keyboard inputType that might be rare but being used by paypal and mapped to “phone” incorrectly.
I hope you will find out more and also share publicly. Let me know if you need any additional input.
Was your repro also just with the paypal app, or do you already have more insights to share?