C# Weird Bug when trying to remove Controls from Group Box -

i facing weird issue. want remove controls group box, not remove controls. seems bug on microsoft's end right now. tried many different techniques of removing these controls, none of them worked. have 2 other methods removing 1 control @ time (and no, cannot call in loop controls) , there works fine. have no idea issue be. knows way around this.

foreach (control c in fieldbox.controls) // not work, removes labels (i have 1 txt , 1 lbl)                 fieldbox.controls.remove(c);              (int = 0; < fieldbox.controls.count; i++) // not work either                 fieldbox.controls.remove(fieldbox.controls[i]);              (int = 0; < fieldbox.controls.count; i++) // still no success                 fieldbox.controls.removeat(i);              (int = 0; < fieldbox.controls.count; i++) // nope                 fieldbox.controls.removebykey(fieldbox.controls[i].name);              foreach (control c in fieldbox.controls) // final answer, outcome did not change                 fieldbox.controls.removebykey(c.name); 

try decreasing counter , removing controls

for (int = fieldbox.controls.count - 1; >= 0; i--) // successful             fieldbox.controls.removeat(i);