Weird knee pain when fully bending knee

Ever since December last year I’ve been having this knee pain that only happens when my legs are fully bent. At first I only had this issue on my left leg but a month later my right leg had this issue too. I started working out since October last year, and I don’t really have any knee pain in my leg workouts. I’ve been on and off with my stretching but recently I have been consistent. I don’t know if my mobility is the issue since I can almost touch my palms to the floor in a forward fold and such. My adductors are pretty tight but I have been stretching them recently. I stretch my quads too and foam roll when I stretch.

I don’t have any other knee pain. About a month or two ago it would sometimes hurt going down stairs but that’s stopped. I also used to hyperextend my knees and stand flat footed when standing but now I’ve corrected both of those issues since March this year. I’ve done a ton of research about this but I can’t find any answer on this. Sometimes if I massage my popliteus it feels better but the pain is still there. The pain is sometimes on the inner side of my knee and sometimes on the back of the knee. This issue is pretty annoying since I have to slightly adjust basic things like getting into bed or sitting cross legged. I can’t sit on my heels too as I feel the pain. Anyone else have this issue and fixed it?