I've identified the problem and submitted a fix for review on our end. In the meantime, you can sideload an updated version of the companion for Android or join Apple TestFlight for the latest beta version.
Android Companion (2.70d1u): Dropbox - MITAI2Companion-270d1u.apk - Simplify your life
iOS Companion (TestFlight 2.64.6 build 6): Join the MIT App Inventor beta - TestFlight - Apple