I also received the update today at 21.03gmt. At first response times of devices and routines was delayed for about twenty seconds and also several zigbee and wifi devices went offline, came online, went offline again and eventually online over a period of about an hour. The release notes did say a bug had been fixed to update devices’ firmware so I am assuming it was a combination of devices updating and the new hub firmware ‘settling down’.
All seems to be ok now. 