I had this same problem and it turned out to be the ESP control. The car thought its wheels were sliding and cut the power to the engine. It was intermittent but on the motorway would make me stop and have to restart the engine. Took ages to diagnose but replaced the sensor and all is well since.
I have a 2010 Navara and have been having loads of problems with battery drain for years. No garages could fix it and the last one said it was a common problem on older Navara’s due to the computer never shutting down completely. I can get a couple of days of not using the car before it drains...