Ok, then X10 has to be very explicit on what platforms and OS it tested on and supports. The iOS app runs fine on my 10.3 phone, but not well on my iPad, running iOS 11 and 12. If the marketing literature indicates iOS, I assume all iOS, unless they say otherwise.
It’s ok to not support *everthing*. This is a daunting task, even for the big guns. Just tell me what works, and I’ll deal with it.