在存储库中保存实体不起作用SPRING

I'm trying to save entity in repository but it does not work at all. Repository is Autowired and in runtime I use saveAndFlush to save entity. I'm using PostgreSQL. Above test methods I added comments with explanation what is going on. I expected that method saveAndFlush should work but it did not. I can not find why. I'm trying to save entity in repository but it