i have an acclerated 6335-SR and factory reset it and the username of root and password default do not work. Any ideas???
If you have updated it to recent firmware and then factory defaulted it, try admin/default.
I believe there are only really three combinations to try:
admin/unique password on label
The unique password is only on devices manufactured sometime post 2019/2020 so I doubt a 6355-SR would be in that.