Choice of fixer on print color

I have a print that seems to be very popular. In fact, it's the only one I've ever sold more than two of. I got another request for a print the other day, so I set up my darkroom and set about printing it. I have detailed notes that I follow for making prints so they are as similar as possible. Same paper, same paper developer, a Pickeresque print map of dodging and burning...you know the story. The one change I made was the fixer. I inadvertently ordered Rapid Fixer instead of Kodak Fixer on my last order. I mixed it up according to directions but did not add the hardener. Every thing went well, I finished making my prints and made an extra just in case. I always use the same dilution of Selenium Toner at the same time. When prints were toned, washed and dried, they looked slightly different.

So I went to the print I have on file and pulled it out. They were extremely close in tonal values, however, the new prints had a distinctly different print color...almost to the point of having blue blacks. It isn't unpleasant, but it was unexpected. Does the fixer have that much effect on print color, or did something else happen in the process that I simply didn't notice. The prints were all made on Oriental VC Fiber, developed in PF's 130 print developer and toned in Kodak selenium toner.

I've been considering switching over to the PF TF-4 fixer also. I'd tried it once before and it was good, but I just never went back to it for some reason. I'm reading that preserves the stain on pyro-developed negatives and that it's very good for prints. Will I get yet another print color change if it use TF-4 for prints? Any experienced opinions will be greatly valued.