Same happened to me when I started adding squats into the mix last year. For me it’s a mixture of age and new workout. I noticed that after maybe age 38 DOMS in my legs hang around for longer than ever before. I committed to a single day a week for legs which included squats and deadlift. I picked Fridays since I do easy workouts on the weekends so I would have time to ease back. Took about 5 weeks for me to move past that phase. At week 3 I was dreading the Fridays workouts knowing what would come. After week 5, I haven’t had a problem since and now really look forward to my Friday exercises.