Middle Splits - Lack of progress

Hello,
I have been stretching my middle splits for months and have seen very little progress. Lately I have not seen any progress at all and sometime am moving backwards. I know these skills take time, but I have been working this since January with little progress. It is very frustrating and I feel I am about to give up on this skill.
7 days a week a do a light warm up, do some squats, then spend 60s in a sumo squat followed by sumo squat bounces. Then I will do 30s in my farthest down split, then 30s further down repeated multiple times. I also stretch in the frog position. Does anyone know why I wouldn’t be seeing results? Thanks