Why do Nitro Boosts and Combat Potions Trigger a Cooldown On Each Other?

Only asking this because its come up a few times where I wouldn’t have died (assuming boosts didn’t malfunction) where when I use a combat potion (Elemental Potion of Ultimate Power) my Nitro Boosts go on a 5 min CD.

Also slightly less annoying, when I use Nitro Boosts my combat potion goes on a 1 min CD.

Any reason in particular why this interaction happens?

Nature of combat potions?

Because engi used to be op/mandatory.

Well half of the issue was the engineer enchants also gave stats (and the best stats at that). Also you could have multiple (boots, haste gloves, frag belt, cloak parachute).

Now a days I dont know why it would be an issue.