Snom m900: default PW doesn't work after factory reset

Hello everybody

A new Snom m900 base station was commissioned, integrated into Peoplefone, a server was assigned, extensions were set up and the Snom m70 handsets were assigned to the extensions.
The Snom base station administration interface was logged into using the default password (admin/admin). On the second day, during further set-up work in the admin interface, logging in with the default access was suddenly no longer possible. We reset the base station to factory settings and tried to log in again with the default access, but this was no longer possible.

Thank you in advance for any responses.