I can't reproduce this in RegTest, Bitcoin Core v27.0

Steps done are: Create a descriptor wallet with default args -> receive BTC -> mine it until it has 6 confirmations.
getbalances shows it under "trusted" balance.
listunspent command shows the UTXO.

The only way it happens at my end is when I purposely lock the single unspent output that my test wallet has with lockunspent command.