I just don’t really get your routine. I think you want to gain muscle but I don’t see a single mass builder in that leg routine. Guess how many walking lunges and split squats Tom Platz did? None.
If your leg routine was all squats you would see more progress. I seem to remember seeing you had squatted before and even then the rep range, weight puzzled me.
I suggest you watch John Meadows’ (Mountain Dog Diet) videos on no bullshit simple exercises. None of these new age, Instagram specials programs.
For example: