I created a folder on my Mac for another Mac to use for Time Machine backups, shared it, and created a sharing-only account for them to access it. Their TM backup completes successfully over WiFi. I set them up to use encrypted backup.
However once they have connected, I am unable to download any iCloud email and the "connection doctor" shows that I'm unable to connect to the iCloud IMAP server. Netstat shows several sockets in a state of SYN-SENT to the iCloud server. Restarting my network connection restores iCloud connectivity — until the next client backup runs.
I have already deleted/re-added the email account, signed off and signed back on to iCloud and these did not help.
Any insight would be appreciated. I'm wondering if maybe the backup encryption is at play but I'm reluctant to remove it. At this point I don't know whether to suspect my Mac or the Wifi router.