370Z Automatic Tailgate Hall Sensor Fault

I had a similar issue on my old BMW 5 series, although it was the trunk. Sounds like a defective cable or plug connection of the component. Have you tried checking the sensor wiring for any obvious damage?

Thanks for the tip! When you say obvious damage, what exactly am I looking for? Is there a specific area of the sensor wiring that's more prone to issues, or a way to test the connection?

With the BMW, the wire loom going to the trunk lid had cracked from being flexed every time the trunk opened and closed. I suggest going to the workshop.

Took it to the shop as you suggested. Turns out it was indeed a defective cable. They replaced it and did some sensor calibration. Cost me 95€, but at least it's fixed! Thanks for the help!