IsParallel() method of Extrema_ExtCC does not give same results in OCC 7.6.0 vs OCC 7.5.0

Hello, I am just moving to OCC 7.6.0 (from 7.5.0) and during tests I found wrong results in Extrema_ExtCC.

I am trying to calculate the distance between 2 concentric arc of circle and depending on the length of the arcs the solution is not always found. In fact the IsParallel() method does not return always true as it did in 7.5.0.

To better understand please have a look to the attached image and code.

Here are below some arc lengths values I tested:

OCC 7.5.0
Angle=30.00 Distance FOUND=10.0
Angle=36.00 Distance FOUND=10.0
Angle=45.00 Distance FOUND=10.0
Angle=57.30 Distance FOUND=10.0
Angle=60.00 Distance FOUND=10.0
Angle=150.00 Distance FOUND=10.0
Angle=90.00 Distance FOUND=10.0
Angle=240.00 Distance FOUND=10.0
Angle=270.00 Distance FOUND=10.0

OCC 7.6.0
Angle=30.00 Distance NOT FOUND
Angle=36.00 Distance FOUND=10.0
Angle=45.00 Distance FOUND=10.0
Angle=57.30 Distance NOT FOUND
Angle=60.00 Distance FOUND=10.0
Angle=150.00 Distance NOT FOUND
Angle=90.00 Distance FOUND=10.0
Angle=240.00 Distance FOUND=10.0
Angle=270.00 Distance FOUND=10.0

Maybe I have to register a bug in Mantis ?

Best regards.
Jerome Monaco.