When Lithium is installed alongside this mod, phased blocks cannot be walked through. you can still interact/mine through them, just not move through them.

Origins had a similar issue in the past where phasing through blocks would cause you to suffocate, and it was due to Lithium's suffocation optimization. Hope that helps.

This is a log of my playsession where I loaded a world and phased a block, then tried to walk into it. (I don't think it'll be very helpful though.)
latest.log