Remember that the IOTA wallet in android is a beta test version, this means that it is a version that can suggest changes and updates since it is in test.
I recently checked my android wallet and found that I did not have all my MIOTAS and the first thing I thought was that someone had stolen them even thought of Hackers, but in the world of cryptocurrency it is important to relax and check the facts.
Android IOTA wallet needs to sync the entire node to give a real read but it does it every time it can sync. (I know this mistake made me see newbie)
But i fixed with refreshing the app by closing it and then adding a new “wallet” address, when I added the new address, the wallet containing the past transactions was automatically added.
This was a complete non-refresh error of the node, and it is not a Tangle detach error, since the tangle may detach or not connect while the transaction is performed and not later.