They are normally down on Tuesdays for maintenance, but it seems they have been down for a number of days, now. I cannot reach SETI@Home nor SETI@Home Beta. And BOINCMgr is not able to return any completed tasks to them. For example:

4/2/2018 9:07:33 AM | SETI@home Beta Test | update requested by user
4/2/2018 9:07:45 AM | SETI@home Beta Test | Sending scheduler request: Requested by user.
4/2/2018 9:07:45 AM | SETI@home Beta Test | Reporting 31 completed tasks
4/2/2018 9:07:45 AM | SETI@home Beta Test | Not requesting tasks: don't need (CPU: job cache full; NVIDIA GPU: job cache full)
4/2/2018 9:07:46 AM | SETI@home Beta Test | Scheduler request completed
4/2/2018 9:07:46 AM | SETI@home Beta Test | Server error: feeder not running

Tuna

SETI Main & Beta ha been having "database" issues since sometime on Saturday.

FROM SETI MAIN BOARDS: Unexplained database slowness

You can always check/post at The Seti is Down Cafe if it is down.