If a Witch drinks a potion, it will not be detected by the Calibrated Sculk Sensor at calibration level 3. It will instead be detected at calibration level 4. However, when the player or a Wandering Trader does this, it is detected. 

Steps to reproduce:

1. Place down a calibrated sculk sensor that is being input a signal with a strength of 3
2. Drink a potion
3. Spawn a witch and hit it, wait for it to finish drinking its potion
4. Place down a calibrated sculk sensor that is being input a signal with a strength of 4
5. Hit the witch again and wait for it to finish drinking its potion

Observed result:
When you drink a potion, the level 3 calibrated sculk sensor detects the action. However, when the witch drinks a potion, the level 3 calibrated sculk sensor does not detect the action. The level 4 calibrated sculk sensor detects it instead.

Expected result:
The level 3 calibrated sculk sensor detects the action when both you and the witch drink a potion.