Thanks for the response, for me at least I feel a pain or strain at the very back of the knee (i.e. at the crease if that make sense?) when I put my left leg in exterior rotation. I’m trying to do the figure 4 stretch at my desk during the day as I’m nearly sitting down all day.
I I have very poor range on my left side so maybe just need to work on the things you’ve mentioned above i.e. hip openers and smashing glutes, adductors etc.
Anyway I’ll work through those first and see if it helps.