Without pictures it’s hard to be certain but it sounds like everything’s fine. Pressure treated wood is usually sold pretty wet from the pressure treating process and when dried too quickly, along with natural tension in the wood, it can cause twisting and checking in the wood. Nothing to be concerned about. 4x4s are more prone to this than 6x6s or larger pieces of timber.
MountainDude769 t1_j923051 wrote
Reply to New pressure treated 4x4 porch posts buckling or twisting by Steiner1988
Without pictures it’s hard to be certain but it sounds like everything’s fine. Pressure treated wood is usually sold pretty wet from the pressure treating process and when dried too quickly, along with natural tension in the wood, it can cause twisting and checking in the wood. Nothing to be concerned about. 4x4s are more prone to this than 6x6s or larger pieces of timber.