My braid was stainless, but had warped due to the other stuck sparges.
As an update, I think I know what was happening in may case. After creating a cpvc manifold, it happened again. I believe what was happening is the piece of aluminum I was using to try and disperse the recirculation water was eventually sinking in the mash tun and sitting directly on the grain. I believe the surface area of that aluminum was creating a vacuum on the grain bed combined with the weight of the wort on top of it was compacting the grain bed to a point of no return.
Once I removed the aluminum, I didn't have any further issues.