EntityGraph defines join implicitly, and I think that

Order order2 =  cb.asc(root.get("chair").get("room").get("name"));

should reuse this defined joins, than creating new ones.

Even more if I define join explicitly

Join roomJoin = root.join("chair", JoinType.LEFT).join("room", JoinType.LEFT);

Order doesn’t use this joins.

Only workaround is to use order like that:

Order order1 = cb.asc(roomJoin.get("name"));

But there is a problem with spring data repositories, which does’t use joins in orders, it create sorting path like root.get.get….