Creating Column Definition seems to generate issues when you use calculations that generate an opposite sign (when row def has checked the show opposite sign). Some approaches for absolute value suggest to use this kind of formula (A*A)^0.5 considering the positive side of the root. It may be possible to add the ABS function to formula calculations, or how can this kind of percentage calculations ((A-B)/B)*100 be made in order to keep the actual sense of the calculation?