I JUST started encountering the same error in a similar environment two days ago. Running both zwave and amazonechocontrol.
Oddly, this setup has been running stable for at least a few months with no major changes to either EAC or zwave bindings.
I’m running the 2.5.0.-2019-09-12 beta version of the Amazon Echo Control binding. Which version are you on? I wonder if it might have something to do with amazon API?
EDIT: Nevermind, just read up on the EAC thread. Seems lots of echo users are having memory issues right now