Okay so it all relates to the reaction timer on mirror mode. For best dropping it needs to be 100ms:
Via the menu: (turn off recommended, turn off allow, scroll reaction to 50-100)
We use a custom dropping system, different to every other scripter on osbot because I believe it helps for humanness so some things need to be configured for best results.
Please tell me how it goes! ^^
EDIT: For anyone wondering yeah so the script has its own default value and if it worked back then better and now it doesn't, it's because I changed the default value from 100 to 1000 from time to time just to see what works best. There is a tradeoff between performance vs responsiveness. Maybe a middle of 500ms can work but never tried it yet.