1 x 6 " Pine ship-lap siding onto a structural panel.
Panel is skinned with 3/8 " OSB.

The builder used 1 1/4 " x 1/4 inch crown staples and the siding was not back coated with stain. Wood was a bit green, so, 6 years later, the shrinkage and warping is pulling the siding away from the Panels. What a mess... Are screws the answer?

Is there a suggestion for fixing the siding short of removing and replacing it?

Also, what sort of fasteners should have been used for ship-lap siding and what should have been the placement?