Odd situation with a new shotgun

[Entryteam]

I figured it out.

[L-2]

No experience with the subject problem.
I've got a somewhat similar Mossberg 590A1, but I've never even touched a Maverick 88.
With a brief glance at the specs, these come in either 12 or 20 gauge with a maximum of 3" ammo.
Except for loading the wrong ammo into the Maverick, I suppose the next thing to consider is there could be something wrong with that Remington ammo; or one's technique.
Find another shotgun with which to try that Remington ammo &/or get another person to get hands/eyes/& another opinion on the matter, in-person. I've got no other ideas. Maybe somebody else here will know the answer without personally being there with the OP's gun and ammo.

[3 AE]

I figured it out.

Why not post the remedy to help others in the future?

[Entryteam]

Why not post the remedy to help others in the future?

You know.. when you do something SO silly or stupid.... that you would only tell your wife, or maybe your brother, or best friend?

THIS.... I take to the grave.