Error on /credentials.html

[jonnytest1]

after typing in a username + password then pressing Store credential I get an error in the console :

Uncaught TypeError: Failed to construct 'PasswordCredential': 'username' must be specified in the form's autocomplete attribute.
    at storeCredential (<anonymous>:10:20)
    at HTMLFormElement.onsubmit (credentials.html:1)

and Request Credential never returns anything

chome://version: Google Chrome | 88.0.4324.182 (Offizieller Build) (64-Bit) (cohort: Stable)

[NOtherDev]

So strange. Does not happen for me. And the fact is that the username field does have the username autocomplete attribute...