Are you weighing your ingreadents for your sauce or just eyeballing? Being unbalanced with your measurements could be the issue.
Or
Have you changed any of the ingreadents,ie milk fir full fat to 2%? Typt of fat or flour in your roux?
Just some food for thought.
Or
Have you changed any of the ingreadents,ie milk fir full fat to 2%? Typt of fat or flour in your roux?
Just some food for thought.