It does sound like standard level 7 bolt stick. You need a shorter spacer than the 0.225 but longer than the 0.215. You can rub one end of the 0.225 spacer on a piece of sandpaper which is laying flat on a smooth surface. That will gently shorten the longer spacer. Once it reaches the desired length, it should work without leaking.
The reason you need the stiffer spring is because it needs to overcome the extra force required to move the oring. That means the oring needs to be held farther back by a spacer. A stiffer spring will only be a stop gap measure and will still cause issues at the most inopportune time.
The aftermarket venturi bolts have been a source of problems throughout the years. They may work fine, but may have different dimensions than AGD bolts. This means that a gun with one of these bolts may need different spacers or a newer sear to work in a gun that was previously working with an AGD bolt.
Except for the Automag in front, its usually the man behind the equipment that counts.