Have you tried plugging the connectors back in? Odd to have them disconnected. If a used car, I'd worry that someone replaced the seat with one from a non-compatible car, and the connectors may be different. Tesla has gone through a number of different seat designs over the years.
Also, you may need to reboot the car - It sometimes fixes oddities. Press both scroll wheels until the main screen goes black. Reboot takes about 1 minute.