Degraded Apple calendar sync

Apple calendar synchronization has returned to normal operation and credentials have been reinstated where the invalidation was related to the incident.

Apple's calendar servers appear to have started responding normally since 08:15 UTC.

We will reinstate credentials where possible in the next 20 minutes so long as things continue to appear normal.

Some Apple credentials have been invalidated during this incident before we stepped in to prevent that process from happening.

Once Apple's calendar servers are responding normally we will reinstate the credentials invalidated during the window of this incident where possible.

We have seen an elevated number of errors when attempting to synchronize Apple calendars across all data centers since around 07:25 UTC.