Telnet or SSH to the unit and login as root.
A user will need to be added with the escape key settings changed (root cannot be used):
#> set user name=(username)
Where (username) represents the name of your new user.
Change the the telnet and connect escape keys for the user:
#> set user name=(username) telnetesc=^o connectesc=^z
This will change the telnet escape character from ^] to ^o and the connectesc to ^z, for whichever user is having this problem. Note that you will not be able to change this for the root user. If you were using user "root" to do your testing, try creating a user named "test", then make the change for that user and test to see if the problem is fixed.
May 09, 2019