In android please don't make a request so close to start of frame where the object are being created and asynchronous operation need some time to set...
I check your apk the admob version does not correspond to version 291.6, I will make an update via Extension Manager and let you know when to update....
I've found a bug with the Get Object on UWP, if you use more than 1 Get Objetc on the same frame, only the last "On Get Complete" will be triggered....