Parking/e-brake light blinking, beeping?

I have a 2002 Jetta 1.8T. So not long after I moved, I notice the E-brake light blinking and beeping temporarily. It seems to occur on hills. It always goes away after a 10-15 seconds. My first thought is that it’s complaining that my e-brake is still on while driving, but I’m definitely releasing it.

I didn’t used to live where there are so many steep hiils and drove on relatively flat ground almost all the time.

Is this a safety feature? A warning of some sort? I can’t find anything in the manual or online… The ABS light is not affected, just the parking/e-braking light.

My daytime running lights are functioning properly.

Thanks.