Tertiary Datum doesn't constrain any degrees of freedom?

This one has me really stumped:

DATDEF/A,FEATURES=PLN_A,,
DATDEF/B,FEATURES=PLN_B,,
DATDEF/C,FEATURES=LIN_C,,

PLN_A        =FEAT/PLANE,CARTESIAN,OUTLINE,NO,LEAST_SQR
              THEO/<-0.420649,0.718,9.894943>,<0,-1,0>
              ACTL/<-0.420649,0.718,9.894943>,<0,-1,0>
              CONSTR/PLANE,BF,PNT_A1,PNT_A2,PNT_A3,PNT_A4,PNT_A6,PNT_A7,PNT_A8,PNT_A9,PNT_A10,PNT_A11,PNT_A12,PNT_A13,PNT_A14,PNT_A15,PNT_A17,PNT_A18,PNT_A19,PNT_A20,,
              OUTLIER_REMOVAL/OFF,3
              FILTER/OFF,WAVELENGTH=0
PLN_B        =FEAT/PLANE,CARTESIAN,OUTLINE,NO,LEAST_SQR
              THEO/<0,-0.343,9.760499>,<-1,0,0>
              ACTL/<0,-0.343,9.760499>,<-1,0,0>
              CONSTR/PLANE,BF,PNT_B1,PNT_B2,PNT_B3,PNT_B4,PNT_B5,PNT_B6,PNT_B7,PNT_B8,PNT_B9,PNT_B10,,
              OUTLIER_REMOVAL/OFF,3
              FILTER/OFF,WAVELENGTH=0    
PNT_C1       =FEAT/CONTACT/EDGE POINT/DEFAULT,CARTESIAN
              THEO/<0.252386,-0.718,0>,<0,0,-1>,<0,-1,0>
              ACTL/<0.252386,-0.718,0>,<0,0,-1>,<0,-1,0>
              TARG/<0.252386,-0.718,0>,<0,0,-1>,<0,-1,0>
              MEASURE ORDER=SURFACE
              SHOW FEATURE PARAMETERS=NO
              SHOW CONTACT PARAMETERS=YES
                DEPTH=0.015
                SAMPLE HITS=1,SPACER=0.19685,INDENT1=0.15
                AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.15,DISTANCE AFTER=0.15,DIRECTION=ALONG FEATURE VECTOR
                ONERROR=NO
PNT_C2       =FEAT/CONTACT/EDGE POINT/DEFAULT,CARTESIAN
              THEO/<0.782489,-0.718,0>,<0,0,-1>,<0,-1,0>
              ACTL/<0.782489,-0.718,0>,<0,0,-1>,<0,-1,0>
              TARG/<0.782489,-0.718,0>,<0,0,-1>,<0,-1,0>
              MEASURE ORDER=BOTH
              SHOW FEATURE PARAMETERS=NO
              SHOW CONTACT PARAMETERS=YES
                DEPTH=0.015
                SAMPLE HITS=1,SPACER=0.3,INDENT1=0.15
                AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.25,DISTANCE AFTER=0.25,DIRECTION=ALONG FEATURE VECTOR
                ONERROR=NO
PNT_C3       =FEAT/CONTACT/EDGE POINT/DEFAULT,CARTESIAN
              THEO/<1.44509,-0.718,0>,<0,0,-1>,<0,-1,0>
              ACTL/<1.44509,-0.718,0>,<0,0,-1>,<0,-1,0>
              TARG/<1.44509,-0.718,0>,<0,0,-1>,<0,-1,0>
              MEASURE ORDER=BOTH
              SHOW FEATURE PARAMETERS=NO
              SHOW CONTACT PARAMETERS=YES
                DEPTH=0.015
                SAMPLE HITS=1,SPACER=0.3,INDENT1=0.15
                AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.25,DISTANCE AFTER=0.25,DIRECTION=ALONG FEATURE VECTOR
                ONERROR=NO
LIN_C        =FEAT/LINE,CARTESIAN,UNBOUNDED,NO
              THEO/<0.252386,-0.718,0>,<1,0,0>
              ACTL/<0.252386,-0.718,0>,<1,0,0>
              CONSTR/LINE,BF,2D,PNT_C1,PNT_C2,PNT_C3,,
              OUTLIER_REMOVAL/OFF,3
              FILTER/OFF,WAVELENGTH=0              

But according to 2023.1, it doesn't constrain any degrees of freedom.

"Datum is invalid because it constrains no degrees of freedom. Datum reference C"

But since it is and Edge it will constrain the last degree of freedom