Do your washers resemble cones?
If so, you could be falling victim to a common headache experienced in some shaft alignment jobs. What could mistakenly be diagnosed as soft foot or coupling strain, “dished” or “cupped” washers center themselves in the feet causing the machine you are aligning to move laterally as you tighten the hold-down bolts. Prevent this from happening by performing pre-alignment checks and replacing any washers that exhibit this defect. Also, check the surface of the machine feet for similar grooves that have been cut by washers in the past. These grooves can also cause this effect and make your alignments challenging.