The eWelink will not pair with D1 dimmer module. Tried several times. I have other Sonoff devices and they will only connect via compatible mode but I can not see how you could do this with D1 module. I have an iPhone X - Software version 13.3
Clearing the code really helped for me. You have to order a rm433 though to do so (they aren't that expensive). Haven't had any issues since.
I finally managed to pair my dimmer D1 with Iphone 11 with Ios 13 to Ewelink. Quick pairing did not work. I did the following: turn on power (electricity) after 1 second turn off, turn on after 1 second turn off, turn on power (electricity) after 1 second turn off, turn on after 1 second turn off, turn on power and go to wifi settings in Iphone. You find Itead wifi. Go to Ewelink app and choose + then choose compatible pairing mode (very low on screen). Send the details of your wifi 2.4 network and it works. It took me an hour to find it out, so I thought I should help you guys by sending this info here.
I finally managed to pair the dimmer d1 with my Iphone 11 IOS13. Quick pairing did not work. I used compatible pairing mode after I did this:
Turn on Power, turn off after 1 second
Do this 4 times and turn on the power.
(You did it turn on for 5 times now)
Go to your Iphones wifi settings and choose Itead network with password 12345678
Go to ewelink app and choose + and choose compatible pairing mode. Now enter your wifi settings and it will work