Items are not being consumed, do not display updated stats instantly

I'm having an issue with consumable items, and I'm pretty sure it must be due to a script that got messed up.

I have consumable items, like potions and stat-up items.  I'm in the menu outside of battle.  When I use the stat-up item, it acts as if the item can't be used on the player, and plays the "Buzzer" sound.  But if I cancel out to the main menu, the player's stats indeed were increased, even though no items were consumed. 

What section(s) in the scripts can I look at to troubleshoot this?  I tried removing my custom scripts, but still no good, so there must be a typo/logic error somewhere in the default scripts.

Could you maybe post a snippet of your items page?

Check for a script that alters the "item_effect" method in Game_Battler, which will likely be a custom CMS (if using) or a CBS or battle add-on.

Check for a script that alters the "item_effect" method in Game_Battler, which will likely be a custom CMS (if using) or a CBS or battle add-on.

Yeah, that did it.  I realized I forgot to try removing this one custom script...

..and, um, it was your "Add-On Collection by ForeverZer0" Version: v.2.8   
I'm guessing something in the Chemist Class was affecting it?  But I have @CHEMIST_ABILITY = false, so shouldn't that code section not run?

It might be a bug with the script I overlooked, I'll look into it, but you can delete that script for now, it won't have any adverse affects.