So based on the new information, including that the ammunition is, in fact, correct for the chambering, I offer a new suggestion. This will sound strange, but hear me out.
Take a loaded round and see if it will insert into the muzzle up to, or beyond the brass neck.
I say this because we are continents apart and it is entirely possible that the barrel bore does not match the chambering on a brand new rifle.
There aren't very many reasons why the point of impact and point of aim would be off by 3 meters at 50 meters.
If it is believed that the scope and mount are correct, that leaves the barrel. This would become obvious with numerous shots fired. But with minimal shots fired, we're left with minimal information to work with.
And now there exists the possibility that the POI was in the dirt?