On iPhones using Comcast Xfinity home Wi-Fi (Arris XB7), FormNX forms fail to load—both embedded and direct links—while working fine over cellular data or other Wi-Fi networks. This appears to be related to how Xfinity handles third-party scripts or iframes. Please consider investigating compatibility with ISP-level filtering and iOS WebKit behavior, and adding a fallback or compatibility improvement to your roadmap.

I do not have issues when using other vendor forms.