If you cannot access the shell on a FreeBSD dedibox from the online.net console, here is a quick tip. Create an alternate root account with csh or tcsh and access ttyu1 on this account instead. That’s almost precisely what the toor account is made for, except that we generally leave the default shell on root.
No idea why sh, bash and zsh are not working through the serial connection, more doesn’t work either, but vi does. Probably a termcap thingy ? If anyone has a clue…