I've been trying to follow 4 day split as described here: https://www.aworkoutroutine.com/the-muscle-building-workout-routine/
The the upper body workouts are no problem. I might be a little bit sore for the next day or two but it's nothing I can't easily power through. My problem is with the lower body workouts. I can do the work outs but my legs are extremely sore for several days afterwards, to the point where its difficult to walk (much less go up or down stairs) even 3 or 4 days after the work out. To compensate I've been increasing the number of rest days after a leg workout hoping that over time my leg muscles will get used to the workout and the recovery time I need will decrease.
Is this the correct solution to my problem or is there something else I should be doing to fix my issues with soreness and muscle recovery after my lower body workouts?