Hey there! As indicated by the description of the Overload Champion icon on your character screen, Strand does not stun Overload Champions. So, by suspending them, which I suspect is what you are doing, you restrict their movement, but you do not disrupt their ability to heal fast. Therefore, in the first example you mentioned, the Overload champion still heals itself against your Gjallarhorn rocket as it is not stunned. For the second example that you use, the use of a Strand knife after stunning the Champion, it might be the case that the animation of the throw takes up a lot of the time that the Champion is stunned. Especially in Master content, Champions can get their abilities back considerably fast. However, certain abilities can indeed "get Champions back up", such as Stasis abilities that freeze the target. While I don't know why this is the case from a technical standpoint, it might be due to the ability overriding the stun that was previously applied (which is indeed not the greatest thing). So, to summarise, it is probably the best way to first stun the champion, then deal damage with a burst weapon to then switch back to your Stun weapon to disrupt the champion again. You may use Strand to restrict their movement, but as mentioned, this won't stun them. Hope this helps and good loot!