My 2018 iPad Pro 12.9 has been intermittently not charging when I plug it in. I could flip the cable around and get it to charge. I use it mostly attached to my Magic Keyboard but also off the keyboard quite a bit. I’ve used various types of cables, outlets, reset the iPad, etc to no avail, and at this point it will not charge at all. I decided to pull the trigger on a M1 12.9 iPad Pro since my peripheral accessories will work with it as well and was looking to trade in but presumably is it not worth anything to Apple at this point?