Slowness and speed potions combined

I've noticed this for a while and haven't found a post on it yet. If you have lvl 20 slowness and lvl 20 speed in the same potion, the "When applied" stats rapidly jump back and forth. Example code:

/give @p potion 1 16451 {CustomPotionEffects:[{Id:2,Amplifier:20,Duration:25},{Id:1,Amplifier:20,Duration:25}],display:{Name:"Splash potion of Glitching",Lore:["^^...Haha...^^"]}}

EDIT: I know this is a minor bug, but I felt like the problem could happen in more than one occurrence.