Calibrated sculk sensors set to listen for drinking and eating (which I will call sculk sensor or sensor for simplicity) do not detect when a potion is drank while in survival mode, unless the potions have been stacked.

I've not looked at the code but it seems to me as if the sensor checks for the item in the player's hand, and it does it after the potion has been turned into a glass bottle. Stacked potions will work, and it will also work in creative mode, meaning the sensor will give an output as long as you still have a potion in your hand after drinking it.