
My last one was similar, we also had another dog at the same time. I never managed to sort it out I’m afraid, it will be interesting to see if anyone can help you more. She did improve a little when she was much older, I used to let the other dog go forward first to greet people, the tricky one would then feel the need to but in to get her share of the fuss.
It was a shock to me to have a golden behaving this way as my previous ones had been totally the opposite. However over the years I gradually met people with goldens acting in a similar way and on discussing this with them I found they all came from the same breeder.
When I was looking for a breeder for my current golden I scoured pedigrees to make absolutely sure there were no dogs that were in the previous dogs pedigree as I felt there was an inheritable behavioural issue there