If the central manager crashes, jobs that are already running will continue to run unaffected. Queued jobs will remain in the queue unharmed, but can not begin running until the central manager is restarted and begins matchmaking again. Nothing special needs to be done after the central manager is brought back online.
Depending on how your policy is set up, Condor will track any tty on the machine for the purpose of determining if a job is to be vacated or suspended on the machine. It could be the case that after you ssh there, Condor notices activity on the tty allocated to your connection and then vacates the job.