Color Readouts Inaccurate at High Values

I'm on C1 Pro v.21 and use color readouts for all edits. New issue today is the high values stop increasing at 240 when I do a levels adjust to reach a clipping point with exposure warning on. The exposure warning does not work when using Recipe Proofing, even with the entire upper range clipped to a white screen, and the color readout stays stuck at 240 whether Proofing or not. Restarting Apple Studio and/or C1 does not restore functionality. Have had other issues in past with this essential tool, but typically will restore normal function with restart. Not this time!