Sounds like blowback although it is likely to be primer fouling as the pressure of your ignited charge is creater than the pressure of the primer thus there will be some of the charge's pressure that finds it's way back through the breech plug and around the primer.

I doubt there is any way of 100% getting around this phenomena.

A tighter fit or seal of the primer into the breech plug will minimize much of this.
Perhaps your barrel to receiver fitment is not quite right.
You may wish to send it back to the MFG to have them verify or have them tell you what the clearance is supposed to be and you can check it yourself or have it checked locally.
Good Luck!