I wonder if the problems would be reduced if the belt were slightly shorter?

The reason I raise this is that on our old 4/4 (Ford CVH) the correct alternator drive belt was shorter than the one fitted to the equivalent Ford vehicle.

Paul
Costock, UK
2014 4/4 Rolls Royce Garnet Red
Disco 5
Teddy - 17h1 Irish Draught cross