My form won't redirect to Paypal when it is submitted on iPhone or iPad

The form worked on my iPhone 6+ device running IOS 11. Did you embed this form? If so, please share with us the page URL so we can further check.

I've tested this form: http://www.jotform.us/form/40495657826164. 

It's likely an issue with embed codes. We suggest using our iframe method if the issue persists: 

https://www.jotform.com/help/148-Getting-the-Form-iFrame-Code