i’d like to chime in and report that the issue of updateSmartHomeState fails with unexpected error java.net.UnknownHostException: alexa.amazon.de is present not only in 2.5.10 (as reported here: Preview and Beta: Amazon Echo Control) but also on 2.5.9
fresh raspbian, docker and openhab installation
this causes alexa devices to not update as well as devices first added as thing w/o simple mode on to never ever gain their functionality (like powerstate), even after deletion and re-adding. which makes them inaccessible in rules and renders them generally useless.
only workaround i am currently suspecting and testing is a full reinstall of raspbian, openhab and docker and meticulously toggling on simple mode before adding alexa devices from the inbox. which is a PITA.
also this does not seem to be consistent - some devices get their functionality straight away, some not at all =/