I have a Zojirushi BB-PAC20 two-paddle bread maker. It had been working fine for years, but recently it stopped mixing right, leaving huge chunks of unmixed flour. I found that the problem was one of the paddles; it rotated freely all the way around the post it mounts on, so when bread ingredients were there holding it in place, the post would have rotated freely within the cylinder, without rotating the paddle. Originally the cylinder had a flat side, matching the flat side of the post it mounts on and which rotates the paddle. The paddle's cylinder had been bored completely smooth and round; no vestige of the flat side. The other paddle had only a tiny nub remaining from the flat side; it would have failed in the same way soon. My question is, what happened to the metal that had constituted the inner flat side of the cylinder? I'm pretty sure we didn't eat bits of metal, and I never saw bits of metal when cleaning out the pan and paddles between loaves. Where did that metal go? UPDATE: Tetsujin asked for pictures. Here's the paddle:  This shows the posts at the bottom of the pan that the paddles mount on:  This shows the paddles mounted on the posts:  
Some thickeners will lose thickening ability if you heat them too much, and as a pressure cooker allows you to get past the typical boiling point, it’s possible that this has happened. But you should be glad that it did— because you shouldn’t cook really viscous things in an instant pot. Basically, you can’t stir things in the sealed vessel, so you need to rely on thermal convection.  If there is insufficient convection, you risk it scorching on the bottom, which acts as an insulator.   The instant pot will recognize that it’s gotten too hot, and displays a ‘burn’ message. Once it cools off sufficiently, it will try cooking again, but if it triggers too many times it will shut off completely. If I were to try making gumbo in an instant pot, I would hold back the roux, and not add it until after the pressure cooking 