You have check the connection between the faces. Class A means
Check the connection between the three faces.
open "connect checker analysis"
G0 is OK between green and blue
Tangency (G1) is OK
Curvature (G2) is OK
so--> CLASS A
G0 is OK between blue and yellow
G1 is OK
G2 is NOT OK, 98,72% difference
so--> NO class A