Hello Joody,
Default Max Qty Level is used for the quantity from which the discount will start. Like if you set default max qty level to 5, Any rule below that quantity will be excluded either it has been set to global level or product level.
Please have a look at my screenshot: https://prnt.sc/wkpjfq
I have set default max qty level to 3 so any rules below this qty will be excluded and no discount will be applied.
Hope you can understand.
Kind Regards,
Rony P – Support Team