No progress on middle splits - tips?

I'm not seeing any progress on my middle splits and think maybe i need some other stretches, so I'm seeking help. A few notes:

1. I'm making pretty good progress on feet-together flexibility (toe touching), but when I split my legs, my hamstrings are super tight and I don't feel like they are getting a stretch. I've been trying for about 6 months

2. Coach Sommer originally suggested I was stretching too intensely, and this was the cause of pain. He was right, i backed off, and my pain is gone, but i don't feel like i'm making much progress, if any. 

3. I've tried rolling out the tightest parts of my upper leg/back of the glute with a ball. It's (very) tender and i've been working on it for about a year. I roll about once or twice a week. This seems to help. It's getting less sensitive and i feel I can stretch further with feet together, but it still feels like there's something holding back my hamstring stretch in the middle-split. 

I know what a "stretch" feels like in parts of my body where I make progress. But, i can't seem to get that in my hamstrings with a middle-split. It just feels like the muscles are being pulled. Not sure what's going on. 

Thanks for any help.

HI Gregory, well if your restriction is more related to the capsule well they need much more time. when did you started to use the programs?

Over 6 months ago and I've been regularly stretching once a week with the side splits (rolling and other days). 

Are you "twerking" your butt out in your isometric middle split? Look at the course video for isometric middle split and you will se what I mean.