S-Mag clicking sound

[Flyhigh]

Hi.

After 4.500km my Brose S-Mag suddenly started to make a continues clicking sound on my Specialized Kenvo (2021). The sound is similar to a chain guide which is not well adjusted (listen to the attached mp3 file).
The sound is louder the higher the motor support is adjusted. It's entirely silent if motor is off.
The motor feeling is normal. No issues here.

It seems also to depend on the temperature. In the morning when it's colder also no sound, but in the afternoon the sound appears.

Any idea what the source of the sound could be and how critical it is?

Thanks for any ideas!

 

[Flyhigh]

The belt was finally torn apart a few days ago. Replaced it, now the sound is normal again. I already had some torn belts, but never noticed this sound, though.