SpringBoot JPA - Many To One relation mapped between User and UserStats, but when I get the User from Repo, has no UserStats entities?
It is probably because you need to add the cascade in order to let him save in cascade
@ManyToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
and also, I am not sure if you are using a LAZY fetchType in purpose, but if at any point you have problems loading some data (I mean, if it is bringing to you just null data) it may be because of it, in that case you will have to use EAGER instead of LAZY