VW T4 Interior Lights: Upgrade & Replacement

Hello, professional electricians!

"I've been bothered for a long time that in my T4 Caravelle, manufactured in 2000, all the interior lights turn on when any door is opened. According to the wiring diagrams for the T4, they are wired in such a way that every light illuminates regardless of which door is opened. This adds up to quite a bit: three interior lights, the step lights, the aftermarket footwell lighting, and the aftermarket red and white lighting in the front doors. I wanted to at least modify the tailgate light so that only the light in the cargo area turns on. So, I did it. On the interior light, there's a red wire (constant positive), a brown wire (ground), and a white-brown wire (door contact for the sliding door). A brown-white wire (door contact for the tailgate) is connected next to it, bypassing the interior light. I disconnected the two brown-white wires and only connected the one from the tailgate, and everything works as intended."

However, there's a HUGE "but":

The car's central locking system no longer recognizes that the tailgate was opened after being unlocked, and it locks the car again after the usual time. If I ever leave the key inside...

How can I avoid this? This darn car doesn't automatically turn off its interior lights after a certain time, unlike Audis and Sharans, etc. Is there a solution to this?

Greetings, Peter.