Potion of Harming Lingering 2 does not disappear! Glitch!

Hi I noticed! There is a glitch were lingering potion of harming 2 does not disappear!

In the game we were trying to get rid of mobs, because to many spawned, and we did not want to use the /kill @e command.

 

So we tried to use lingering potion of harming 2 and it would not get rid of the potion effect!

they just kept glitching and staying there.

 

 

Anyway GOD bless! Thanks