How can i guarantee a specific item always drops from a specific enemy?

I’ve tried overriding zombie_a01 to have only a single misc equipment with no other equipment, and the chance cranked up high on all values however I cannot get it to drop anything even once. Am I missing something or have I likely configured myself into an error that is being suppressed and therefore nothing is dropping? Is there a log file that might highlight this? Thanks!

I’m going off memory so it may not be 100% accurate.

ItemCategory1 - Should be set to 100
(You have a 100% chance of obtaining an item in category 1)

Below that is the Weight per item. In your example all of them should be set to 0. Then the item you want to drop should also be set to 100. Note: there must be a database reference to the item you want to drop.
(So 100% of the time an item in category 1 should drop and that item should always be the one set to 100%)

If you want an item to drop with a 1/450 chance

Use a calculator to do 100/450
So .222 would be your initial drop rate. This same formula works for any chance.