I have no clue how support for the PPA provided Ubuntu NC client works, but with the latest 2.3.3 update released a day or so ago, it seems that the client has a grey icon all the time.
This used to imply that connectivity was broken and some administrative action was required on the client and/or server.
When I look at the folder sync status icons they each are grey and say “signed out” if you hover over them.
Is this now a new expected behavior for normal functionality? Or does this means that there is a problem somewhere and a bug needs to be reported?