When C is decomposed it is diffrent from the color picker

[jarj]

Version: GIMP 2.10.36

   

I have a simple image      2x2 RGB(54,58,83) and the color picker converts this to CIE LCH
L = 24.9% C =  16.2% H =  282.3°


if I do Colors → Components → Decompose [uncheck 'Decompose to layers' ] and look at the L C H images the RGB% are: 
L = 24.7% C = 8.2% H = 78.4% (78.4 * 3.6 = 282.24°)



L and H are pretty close, however C is 50% out - What am I doing wrong or misunderstanding or is this a bug?


and help or workaround much appreciated