I have a similar issue with my 2011 LR4 where the key fob not found error occurs a couple times a year . My workaround is to pull the 5A fuse (R7 I think) and reinsert. Wondering what you've discovered?
More issues now - Now I can't start at all, even with the bypass Near Field -
New Codes now -
B1B01-81 (2E) Key transponder - Bus signal/message failure - invalid serial data received
B1 B01-55 (2E) Key transponder - System programming failure - is not configured
B1B01-87 (2E) Key transponder - Bus signal/message failure - missing a message
I was getting my local tire guy to install new tires and had to replace some brake lines, and the shop said it would try to look at the codes with their machine - they cleared it, and it won't start. Not a Land Rover Indy garage.
Now I am worse than when I dropped it off. I have an appointment at the Land Rover Specialist next Friday... will get it towed there and see what he says.
@rniederer - I have done multiple battery disconnects and have pulled the 17P fuse. no help for me