I bought a PowerLine+ Lightning cable last Feb 2018. Just this August, I started experiencing connectivity issues with my anker cable. I always encountered this pop up "This Accessory May Not Be Supported" every time I charge my iPhone. Went to where I purchased my cable and I was informed that a lot of people have also experienced same issue.
an Anker Employee told me that issue might probably due to the iOs update of Apple. Mine is on ios12 now but issue started when I was still on iOs11. They changed my cable to brand new, thanks to the 18-Month Warranty, but unfortunately I am still encountering the same issue on my phone.
I thought that the issue might probably due to my charging pin but I also tried charging my phone using my old apple lighting cable and no issue encountered.
Hope you could provide some feedback/help before I send my new cable again to customer support.
I also tried rebooting m phone by pressing POWER+HOME but problem still not solved.