Maybe a bug in the wallet ?
It's not a bug unless he can't send his BTC. OP probably sent it on his older receiving address and it got buried somewhere since electrum uses new receiving address after 1 incoming transaction. It shouldn't be lost if his wallet shows 0.016 btc the receiving address is the only missing part anyways it's not needed when sending BTC.
This is due to BTC diggers, which may cause the BTC to wear out
BTC diggers causing BTC to wear out? Lol what are you talking about. If you meant the miners they have nothing to do with OP's problem.