I have just played a league match against a team where every one of my players was significantly stronger than their opponent. Every scrum drove them back providing my scrum half with perfect ball and yet not once was the ball passed out. Each possession from the scrum resulted in my nine or a back row player knocking on leading to a new scrum. I scored the only try of the game in the final few minutes when my opponents possession lead to a turn over. Surely it can't be correct when. My nine, eight and ten are all ranked 30!

They can be tired or lacking morale. Also there own instructions or your team strategy might not be the right options for your players

Morales high and the fitness was good, scrum half was in the nineties

Not sure about individual,strategy however I think it's fine as I've been through them all individually

Well i had the same issue...still happens sometimes...now i just let them get 100% on energy and morale and put few of their instructions lower and they seem to do it lot less

Do you have a high kick rate in strategic instructions ? Maybe try to lower it.