Well, I haven't ever taken the boots off (yet, but I'm sure I will to straighten the pants like you did), so I don't know what 'black foam' you mean, but it sounds like the ankle joint isn't fully engaged.
The barbell needs to be firmly fixed to both the foot/boot and the leg.
The barbell needs to be firmly fixed to both the foot/boot and the leg.
![140.jpg](https://proxy.imagearchive.com/b9a/b9a82bc1c4b2529d4ce01cb61e2eabd3.jpg)