I have a Phantom 3 standard and have seen posts that state the Iphone 8 is no longer compatible.  Is that correct?  I still have a couple of Iphone 7s but they are not active and when connected I have the 50 meter limitation, is there any other option then adding the Iphone 7 to my cell service account?

Hello and good day. Thank you for reaching out and for the inquiry. Upon checking the said mobile device ( iPhone 8 ) on the recommended mobile device list. I am sorry to say that the iPhone 8 is not listed on the said list for the DJI Phantom 3 Standard. I would suggest using a recommended mobile device that is listed on the recommended mobile device list for your DJI Phantom 3 Standard for compatibility and reliability on both the said drone and of the DJI Go application. For reference I will be posting the list of recommended mobile device for your DJI Phantom 3 Standard. Thank you for choosing DJI and for your support.

Did you try your 8 to hook up with your P3S yet?

The 8 should work fine.  Make sure you're not in beginner mode also.

...and make sure you´re logged in to DJI via Go app.

All of the latest iPhones work perfectly with the Go app as they do the Go4 app - you should have no problems. In fact, the more modern processors should make the app run more smoothly.