I have a 8 month that looks very straight in the rear right now. In the 8 week photo's the rear looked ok. I have never experienced this before, is this likely to change?

It's a waiting game. Hopefully the rear will change. I've seen it happen at about 15 months but then again it might not. Nothing is certain in this hobby.

It is really not a good age to make a judgement call. Maybe at a year. Give it a little more time. They should come back to what they appear at 8 weeks.