Ok so this one is a little more complex than the title suggests. Originally I thought that I was being locked out of the overcharge mode but after some further testing I found that the bug is acting completely differently from what I originally thought. If you wait for the timer on Void Leech to tick down to 0:00 and then shoot a void debuffed target, you will steal the void debuffs and it will show them on the gun model but you will not be able to trigger overcharge. If you steal ANY void debuffs (even ones it visually shows you have) after entering this state, it will allow you to overcharge and use any debuffs that are visually stored on the weapon. In my final testing, 1) I went to a lost sector and hit the boss with my Mobius Tether to leech Volatile and Weaken then switched to Overcharge mode. 2) When the timer reached 0:00 on overcharge mode, I continued firing until the gun visually showed that I leeched both debuffs and "Void Leech Charged" did NOT show up on my screen. 3) Then while in this state, I shot the boss again while he was ONLY effected by Weaken. Stealing this allowed me to Overcharge again but did not change the visual indicator as Weaken was already stored on the gun. 4) When I went into overcharge, I was applying both Volatile and Weaken to the boss when I should have only been applying Weaken (Volatile was picked up back in step 2 and faded from the boss before I leeched Weaken to ready Overcharge mode). I think there is something wrong with how the game checks debuffs and whether you are in overcharge mode or not and gets confused.