Unexpected “Google Assistant Headphones” notification

[op3]

When using the app with Bluetooth and tracing enabled, the following notification popped up several times:

🎧 Google Assistant
Google Assistant Headphones
Google Assistant for your headphones is running in the background

The notification occurred at random places in the public, e. g. when taking the train or walking by houses in the street. I don’t have any headphones, and never paired with any headphone-like devices. I assume that my device is detecting the presence of a nearby Bluetooth LE headset.

This issue seems similar to the one mentioned in this issue. I don’t know if this is a general problem when having Bluetooth enabled on Android, but I could not find any similar reports online.

Device: Samsung Galaxy S8 (SM-G950F)
Android-Version: 9