I don't have a solution but there might be a similar issue discussed in this haystack of forum chromebook discussions https://community.appinventor.mit.edu/search?q=chromebook .
You might look through these discussions while waiting for others provide you with possibilities.
App Inventor is a web app, so that might have something to do with your issue.
Chromebooks do work with app inventor (at least some of them). See this recent post Chromebook - Can we use MIT App Inventor? . Some chromebook versions evidently have issues w.r.t. App Inventor.