I've lost funds on android wallet before and the mistake was mine, what I did wrong was going into playstore to look for random BTC Wallet because the one I was using then have no option to edit transaction fee and a heavy congestion was affecting Bitcoin transaction speed at the time.

I ended up downloading a fake crypto wallet which cost me a total lost of $400 or so at the time, Bitcoin was even still at 17k then. The wallet was automatically set to move funds out once you make deposit, I lost the money before I knew that I messed up.

Make sure you stick with original BTC Wallet for android like Electrum or others, also download them from the official website instead of going to playstore and type in the name in the search bar, you could end up with the wrong one.