Additional material of this report: http://rpubs.com/ranghetti/sptransform-issue .

This draft shows an issue occurring using spTransform() with rgdal >= 1.5, which sometimes causes reprojection failing. In particular, we encountered an issue when one (or both) among input and output CRS are associated to a WKT2 in which the axes order is Y – X instead than X – Y (these two situations were hereinafter called “YX CRS” and “XY CRS”). Issues do not present using the “old” method involving PROJ.4 strings. We debugged the code in order to understand where the error is, finding that it occur in "transform_ng" method called by spTransform(). We were not able to fix it, being in a C method and not in the R code chunks.