Variable refs lost in Observable.interval().subscribe() using Ionic DevApp

This is meant to be a bug report for Ionic DevApp (not looking for help)…

I’m using Observable.interval(myInterval).subscribe(() => { ... }) in an app I’m building. Some variables are updated within the { ... } code block. When I run the app as a web app or on my Android phone, everything works fine. When I use the Ionic DevApp emulator to run it on my phone, the variables that are updated in the code block are lost. I get the same behavior when I use plain old setInterval(() =>{ ... }, myInterval).