Submit Button on Fillable PDF not working on iPad

[#1]

I created a fillable PDF form in Acrobat Pro DC with a "Submit" button at the end (see below).  The button is working fine on Adobe desktop applications, but is not working on iPads or iPhones using the Adobe Reader app.  Any suggestions?

[#2]

Does it have an http/https URL? Don't think email can work (not recommended anyway, too flaky).

[#3]

What are you talking about? Mailto links are quite popular, and they DO NOT work in Reader on the iPad. They work everywhere else and I've used them for years. Acrobat will not even invoke the Mail app on the iPad so the email can be created. It simply puts its own pop-up (yes, a pop-up) over the PDF and this "acrobat reader pseudo-email" has NONE of the mailto parameters added. They re-write an entirely different subject line, no addressees, no CCs, no subject, no body. Nothing. The PDF and the email body are set as attachments and the whole email is worthless and ugly at that point. What good is this in the field? Please tell me which freelance programmer sitting in his bedroom has written the app that fixes this HUGE oversight. I'm livid about this, I hit a brick wall here. Here's the code for the button that has worked for years and everywhere else.

mailto:recipient@domain.com?subject=Subject of email&body=Please review the attached PDF form. Thanks and have a great day!