This might be a bit of a long shot but i will still give it a try to ask in here. Might be someone who has experienced something similar.
I'm not quite sure when i got this injury, but it definitely got worsened or might even have started 2 years ago doing a mobility class. We were practicing the pancake and had a person to push on your lower back. I remember i could feel the pain in my right back/inner thigh, but i didn't really say anything (ye, i know it was stupid and i really regret it now). To day, 2 years after it still not good, i don't have any problem during the daily work, and i only feel pain when i specifically stretch in split position or like the pancake. Nothing at all when i'm doing butterfly stretch for instance. I've been to doctor and physiotherapist and they haven't really been able to identify the injury. I've tried several exercises from the physiotherapist but it hasn't got any better. i've tried longer break etc. The pain is like a stinging pain from the groin and all the way to inner knee. The pain only starts when i get into the outer position the feeling is like if i go any further i will get a injury like a ruptured muscle. I know thats probably not the case, but more to indicate how the pain is feeling. I think the injury might be located to the m. gracilis, but not certain about that either. It has just been frustrating for so long now and i don't really know what to do or how to rehabilitate it. So i hope someone might have any ideas or might have experienced something similar.