Hate that feeling when you know the old system was fine all along...

Honestly, that sounds like the dough was doing you a favor by becoming a hockey puck, at least you got a free garage sale souvenir out of it. Tbh, over-proofed bread just builds character, next time aim for a doorstop.

Saw a welder do the same to me back when I was grinding beads on some gate frames. He told me I was pushing the grinder into the metal like I was trying to prove something. Said to let the wheel do the work and just guide it. Next day I backed off the pressure and my welds looked twice as consistent, plus the discs stopped burning out in ten minutes. Still think about that every time I pick up a grinder. Funny how those offhand comments stick with you.