Problem with Leg Rig

Title sounds a bit weird, and maybe my “problem” is a really basic one, I dont know ^^’ but this really bugs me. I cant really explain it, so here is one pretty picture:

Leg moves like its supposed to be until I move it a bit higher than…

Snap! he breaks his legs. I have a slight suspicion that it trys to bend to the pole bone, but I have no idea how to fix this. When I parent it to the leg, it spins out of control, and adding location consteraints doesnt do anything? maybe im doing it wrong, I am a complete beginner after all. can anyone help me :(?
I cant give you my blend file, because new useres cant attach files apparently :/. And I can only post one picture…

I made a gif, this should explain it!

I didn’t realyl tried to understand what you wrote, sry, but I thought i post this video just found yesterday: cool tips in there regarding the pole