I will assume that you are looking at the water tab within the recipe and not the separate water profile tool. The separate water profile tool does not split the additions by initial infusion and sparge.
If you are getting a split of salt additions when doing full volume BIAB, then check your mash profile. If it is set up as a full volume BIAB, then there will be no sparge volume calculated and the program will not split the water agent additions based upon the infusion and sparge volumes. Since you indicated that you are doing a full volume BIAB, set your mash profile to indicate that by clicking on the box that reads 'BIAB with full boil mash' or switch to a BIAB profile.