When there's a fold, the number of lines up or down considers a fold only as one line; but the relative numbers package uses the actual relative difference in lines. In the following image, if I run d9j (in vim mode), which ideally should delete up to the const line, it actually goes 9 visible lines down, which is far beyond the const line.
When opening/closing a fold, for some reason the line numbers below the active line change to absolute. In the same example as above when I open the fold, this is what happens:
Custom Settings in config:
d9j(in vim mode), which ideally should delete up to theconstline, it actually goes 9 visible lines down, which is far beyond theconstline.