Quite a few people have reported problems with zigbee devices after each of the last two hub updates…
We will begin rolling out Samsung SmartThings Hub hotfix version 0.45.11 starting Monday, October 31. Once downloaded, your Hub will briefly go offline as it reboots and applies the update; most customers will experience less than one minute of downtime. We will update the status page when the release is complete.
(the second update was supposed to have fixed zigbee problems introduced with the first update, but some people have reported it made things even worse. 
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