I haven’t setup an iPad with CE. I can only tell you what works on my iPhoneX. Rose Point is the authority and I yield to them for the best info.
I apologize in advance for mentioning things you already know and have tried.
I assume you connect with the iPad using wifi and are not using wired serial communications / usb / lightning connector or other communications connection.
You write you only see position on your iPhone. GPS position data might be coming from your iPhone location services instead of the boat NMEA network. There was a way to turn that off in older versions of iCE. I turned it off in the past and now I can’t find the setting switch to do that on the latest version (v.53.2 from the Test flight beta app). I may just be missing it or Rose Point may have chosen to remove the setting switch and place that important decision into the CE system software logic.
iCE works on your iPad so that indicates that the boat NMEA network and associated instruments are working as they should. That pretty much leaves the problem with your NMEA wifi connection and/or with the CE Electronics Device setup.
My iphone connects with the NMEA network through a wireless router. which communicates with a wireless NMEA gateway.
Check the wifi network connection settings on your iPad and connect your iPhone to the same wifi connection. On my iPhone the cellular data connection works independently and does not interfere with boat wifi for iCE or windows CE.
Your iPad may use a browser and webpage to communicate and administer settings on your boat wireless router / NMEA gateway so once your iPhone wifi setting is the same as your iPad and after it looks like it is connected to the boat wifi see if you can connect to the same admin site with it. You don’t need to change anything you just need to verify the wifi connection and capability at this point.
A browser may use either an ip address or a webpage url to get to the router admin site. The Safari browser on the iPhone can do the same thing.
For security reasons wifi networks are sometimes configured to allow connections only from specific computers or devices based on device mac addresses, network location or other network name, port, or address. If you can’t connect with your iPhone, this might be a reason. That security is administered on the router / gateway.
If wireless network connection to the iPhone is working then check CE Settings_Electronics_Devices on your iPad and set your iPhone to the same settings.
You will use either NMEA 0183 over TCP or UDP. Use the same ip address and port for TCP or just the same port for UDP that you see on your iPad.
The NMEA 0183 over TCP should indicate it is a listener.
A recent communication from Rose Point said that the NMEA 0183 talker is available only with the NEMO device but not with other wireless devices. You don’t need talker capability to see basic instrument, heading, weather and AIS data. There are only a few instrument displays available in the current version of iCE.
I don’t have a NEMO device. My understanding is it communicates to iCE with an ethernet connection to a wifi router.
Your iPad CE works and that it suggests NEMO function via wifi is good. But perhaps NEMO has a special port setting or security feature which controls what network devices might connect to it. I’d have to ask Rose Point about that.
Hope this helps.
sv Salish Breeze