They don't use D-76 in those big machines. They use harsher chemistry. Frankly I can't explain the lingering purple of home-developed film, but I've almost always had it. The only thing I've learned from my years is that the pre-wash water always pours out dark, and developer does not, if I don't pre-wash. So that means either the development "sets the stain", or there's some kind of chemical reaction going on. But the fact remains that the pre-wash water pour out nasty and dark, an the film comes out less purple. After that, don't worry about it. I think it fades a little in time. Always more purple when fresh out of the tank, wet.
You don't have a problem, you did just fine.