Could be that it has something called Remote immobilisation, this is a box of tricks hidden under the dash somewhere ,...used to immobilise a car or van from a long distance away, usually fitted to fleet vehicles and hire vehicles.
that would be my first check.......sorry don't know any more - only you have to get in touch with last owner if it has one ,.
salvage rebuilds youtube channel had such a device on one of their buys ,,less than a month ago
not in the titles, so you are going to be watching ten mins of each video to find it
https://www.youtube.com/@sruk/videosall the best.mark