Update of user through Mgmt API triggers Password Change. Why?

I bulk imported user with email address, user id and a custom password hash into a Auth0 database.
I then synced additional data (mainly name, app_metadata) through the update function of the Mgmt API.
I checked the logs and saw that for each update I also have a log of successful password change.

Why is this password change triggered? Am I missing something in the docs? I feel like I’m getting mad here.