Bug in CurveLinearColor makes colors of Diffraction material white outside curve range, causing rendering artifacts

There seems to be a regression with linear textures (commonly for multi-channel masked textures) in UE5.4. Setting the "Encoding Override" (under Texture > Advanced > Source Color Settings) to "Linear" shows different colors on UE 5.4 vs UE 5.3. The colors seem to match up much closer when setting the Encoding Override to Linear in
UE 5.3 and to sRGB in UE 5.4

• Open a Third Person Project Template project

Look at the mannequin model up close in the 3d view.

Before this was fixed, the rainbow diffraction shine on the model had a hard transition to a banded white.  After the fix it is smooth.