Not only the cache gets corrupted, but the @PostLoad lifecycle event gets triggered before the entity is completely assembled. During the @PostLoad, the references are all still null.

I've constructed a testcase that demonstrates both issues. The @PostLoad contains a System.out.println for the reference, which you can see is null. It finally fails on the entity being loaded from the 2nd level cache with a null reference. For this test, I had to select CacheConcurrencyStrategy.NONSTRICT_READ_WRITE. I’m not exactly sure why, but with the default strategy the cache was not updated with the results of the query. I ran into this issue in our application on WildFly 27 (with a patched version of hibernate 6.1.6) and an Infinispan cache, and we do not specify a CacheConcurrencyStrategy.