FTP sync (changing 'mode' again once it's been changed)

I hope I'm not being silly... but I cannot for the life of me figure out, once I change it once, how to change again, the Mode for for the 'Synchronize...' option.  It just remians greyed out once changed and is impossible to change back unless I delete the connection and recreate it the connection with a different name.

Please help, this is drinving me nuts!

TIA