Is it possible the following in the plugins part in build.settings can cause problems:
["plugin.google.iap.v3"] = { publisherId = "com.coronalabs", supportedPlatforms = { android=true } },
compared to the following:
["plugin.google.iap.v3"] = { publisherId = "com.coronalabs", },
With the first one my app exited at start with an error the plugin.google.iap.v3 wasn’t found or couldn’t be loaded. Changing it to the second now seems to work.