The problem probably lies in LoadQueryJoinAndFetchProcessor.renderManyToManyJoin, which

• calls JoinFragment.addCondition(manyToManyFilter),
• which feeds the "where" condition,

while QueryJoinFragment.addJoin

• calls JoinFragment.addJoin(..., conditionsAndManyToManyFilters) for outer joins,
• which feeds the "on".
• (OuterJoinable.addManyToManyJoin -> ... -> QueryJoinFragment.addJoin)