Project communication failed

On my main computer (Windows 10), my BOINC manager has stalled with these messages:

31/05/2020 18:49:36 | | Project communication failed: attempting access to reference site
31/05/2020 18:49:38 | | Internet access OK - project servers may be temporarily down.
31/05/2020 18:51:22 | | Project communication failed: attempting access to reference site
31/05/2020 18:51:23 | | Internet access OK - project servers may be temporarily down.

This is after I suspended all tasks, rebooted, then resumed all tasks in case problem was at my end.

The multiple Raspberry Pis running on stand-alone configuration appear to be working fine and fetching new work. Screenshot of tasks show all trying to upload.

22:40 BST Seems to be recovering now, so one of the servers must have been down?

Could have been project maintenance being performed, I have seen that happen as well.