Your Pre-Rinse wash

Are you aware why your pre-rinse water temperature should not be higher than 45°C, but also not lower than 35°C?

Proteins will denature when temperature exceeds 45°C, making it more difficult to clean

Fats will solidify and adhere to surfaces when temperature reaches below 35°C Denaturation can occur when proteins and nucleic acids are subjected to elevated temperature they lose the quaternary structure, tertiary structure, and secondary structure resulting in Milk Coagulation and Protein Denaturation.

Have you seen fat globules in your filter , do you mistake it for mastitis ?

Check your filter after your wash and see if there are any signs of denaturation or Coagulation