Just signed in, viewed the group and both maps show up for me with the maps. Make sure the account your using to view on the Android app have access to the maps either through a group that they have accepted the invite too or they own the maps with the account they are signing in with.
We are trying to sync these points in equatorial guinea, could it be that our internet is too slow? We are testing out the collector app, but we need to be able to sync way more than 20 points at a time.... is there a way around this?
There is an issue with Android with a size upload limitation that we are working on a fix for right now. What error are you seeing when the sync fails on Android?