Mercedes B Klasse anti theft alarm issues

I had something similar with my B Klasse. It turned out to be a weird battery issue that was messing with the alarm system. Have you checked the battery recently? Sometimes a weak battery can cause all sorts of strange electrical problems. It's like when your phone is low on battery and starts acting up.

Interesting, I haven't checked the battery specifically. The car starts fine, so I assumed it was okay. Was your car showing any other symptoms besides the alarm malfunction? Also, was it a car alarm false alarm or just a non functional one?

The car started fine for me too. The only symptom I had was the car alarm false alarm going off randomly and an error message. The workshop said the alarm system was coded to activate optical locking, which caused the issue. They fixed it pretty quickly. I would suggest you visit the workshop

Thanks for the advice. I took it to a workshop, and you were spot on. The anti-theft system was indeed coded to activate optical locking, which caused the malfunction. Recoding it fixed the problem. The repair cost was 45€. Appreciate the help!