[SOLVED] Potion Effect Start Procedure doesnt work completely

Im trying to make a potion effect which gain stronger effect for each consecutive hit.
But the NBT variable doesnt increase from the second hit (checked from command message).
The variable starts at 0 before hit, gain to 1 (or 2 if amplified) after the first hit, but stuck at 1 (or 2) even after the 2nd to 5th hit.
https://imgur.com/CSChtsB

If this question exists and already has been answered, please send me the link.

Thank you