These models do not work with native ComfyUI INT8, and will need to be converted with this tool.
Unless you already downloaded these models, I recommend finding a more recent INT8 quant from Silveroxides to avoid having to do this.
Various INT8 ConvRot models for the INT8-Fast node https://github.com/BobJohnson24/ComfyUI-INT8-Fast
These are very unlikely to work on other INT8 nodes until they update.