Re: Worldwide routable Garmin maps: URL REMOVED

Question for UK Mkgmap experts ... when routing from M4 South wales to the M5 West country, Mapsource (and the Zumo) refuses to use the M49. It routes through the Almondsbury interchange.
All avoidences are off, and shortest or fastest doesn't matter, but if you add a shaping waypoint on the M49, its OK.
What is it about the M49 it doesnt like, as its clearly its the preferred route on the ground.
Is is the Construction Area that the M49 currently runs through, that throws it ?
(All works fine when using directions on the web based map). 🤔