have a look on this whether it helps  

Thanks ‌, The form does have some rules that are using operators rather than functions like == instead of equals(). I will try to change them and update the post if that fixed it.

So here is what I found. Some validations rules were fixed such as comparing boolean values and number values. But the one that didn't work was comparing a date of a field to be greater than the current system date which was checking if the date is not in the future. The current date is one of the common fields (not the named fields). Android was passing it, but not iPhone. So to solve it, I had to de-link that field by removing it from the mobile version, and readding it from the list fields which removed the link between the desktop and mobile. Then I kept that one validation on dektop, but removed it from the mobile. That's the best I could do. 

anyone knows why would the following function is unable to pass on iOS?

greaterThan({self}, current date) 

where {self} is a date field. The propose of the rule is to check if the date inserted on the current field is greater than the current date, if yes, then throw an error to say that the date cannot be in the future.

greaterThen() compares strings not dates!

read carefully its description in documentation.

if date (objects) are supplied to the function it compares whether two date objects passed in is the same javascript  object, not whether they represent the same date value.

it neither can work on desktop!

read this discussion on how it could be fooled - Condition on Date Values Returns False instead of True