WebAdmin: invalid username or password, after apply system_password_reset (utm 9.709-3)

Hello

i could not login: WebAdmin: invalid username or password

so i did a system_password_reset,via init=/bin/bash
it seems ok, but after setting a new password, i still got WebAdmin: invalid username or password

so i did system_password_reset,via init=/bin/bash a second time
but again no success, i still get: WebAdmin: invalid username or password

Version: 9.709-3

any help appreciated

Thanks