Reworked and adding a another full block above the egg, the drowned were able to find it. Weird though why the egg didn't break without the two blocks of air above if signs and gates don't count as air.
Not a duplicate, OP describes the bug as happening under water. This happens on land. Drowned just ignore turtle eggs (don't exists, don't care about them).
Reworked and adding a another full block above the egg, the drowned were able to find it. Weird though why the egg didn't break without the two blocks of air above if signs and gates don't count as air.