Recently when I’ve been squatting, my upper glutes have been getting stupidly tight during my squats. It doesn’t occur right away but maybe after the 3rd set I start to feel it! It gets to the point where its painful to stand up straight. I warm up with foam rolling the entire area inc legs then warming up by starting off light and working up to my working weight. The tightness doesn’t hang around too long and by the evening its fine. In 2 years of lifting I’ve never had this problem.
Any ideas on how I can fix it?