I have just updated my iPhone 6s plus to iOS 12 and have already tried all suggested methods minus reverted it back to iOS 11. My main quest is will the next iOS 12.1 patch fix these constant wifi connection issues? If this isn't addressed by that patch I don't see the point in updating to iOS 12.1 after I revert my phone back to previous iOS 11.
try turning off (in settings) bluetooth
I just unplugged my router for ten minutes; it appears to have worked [so far so good]. I'll keep you posted.
I have the exact same issues as you do, on the same device, iPhone 6S Plus.
Here's a screen recording with the mentioned problem on the iPhone 6S Plus and the same test running on an iPhone 6. The conditions were the same:
-same Wi-Fi AP selected
- sametest server selected in OOKLA Speed Test app
-same iOS 12 on both devices
- testsrun at about the same time
iPhone 6S Plus / iOS 12 Wi-Fi test - YouTube
Iphone 6 / iOS 12 Wi-Fi test - YouTube
As you can clearly see the iPhone 6S Plus definitely has serious Wi-Fi connectionsproblems under iOS12.
Apple has a serious problem with this and needs fixing it ASAP!
Does Apple even acknowledged this?
My iPhone 6S Plus doesn't work at all on any Wi-Fi network, even after the recent 12.0.1 update. Do I need to state how important Wi-Fi connectivity is regarding a mobile device?
Mods?
I have the same problem but with 12.1. iOS on iPhone X.
I have done everything, including a restore!!!
APPLE ... PLEASE FIX THIS PROBLEM.
iOS 12 wifi connectivity issues
