Just loaded ios 11.2 on my Iphone 8+ ,loaded dji go 4,and connection worked to my Mavic. Its the first time it has worked since I got my Iphone 8+ 3 weeks ago.
Will carry it out in the morning ( its dark now) to test flight and will update if needed. So far, one happy flyer.

Looking forward to the update to your post. I just updated my phone right now. I too will try to fly in the morning. I have a iPhone 7 wish I have a 8+ or even the X