OneToOne(LAZY) links produce different queries by findOneById for similar entities

Hibernate ORM
1

Hibernate 6.6.16.
Bytecode enhancing is on (dirty + lazy only).
I have Deal and Participant entities with bidirectional @OneToOne(LAZY) fields. Deal has 3 such properties. Participant has 11.
findOneById() produces different SQL queries:

  1. for Participant it fetches only row from participant table (this is what i want)
  2. for Deal it fetches row from deal table + all OneToOne relations by separate queries.

Why?

2

Hard to say with this little information. Please share the full mappings of the entities involved.