I have finally succeeded in registering the remote ID for my Lite+. After several emails with Autel tech support, they escalated the problem up the chain. About a week later, I got a reply to try “1748CLT0xxxx”, where xxxx is the rest of the drone serial number. That worked. Note that they said LT{zero}, not LT{letter O}, which is what is in the drone serial number. That is, 1748CLT0xxxxx, not 1748CLTOxxxx. A subtle difference. The latter was one of their earlier suggestions, and it didn’t work. But thanks to Autel tech support sticking with the problem, the job got done. I have no complaints about their tech support. But why all this was a problem in the first place is another matter.