Listings Losing MPN and Brand

[rakdistribution]

I'm having an issue with listings losing their category specific information and it has stated occuring in the past week. Specifically the MPN & Brand for listings are reporting back as missing.

I update my inventory using the File Management Center and I only have 3 columns referenced in my upload; the Action, ItemID, & Quantity. 

It seems that the data is coming up missing AFTER an inventory/quantity update for my listings.

Has anyone else experienced something similar or have an idea what could be driving this issue? This is causing GTG listings to end and not be relisted due to the missing category specific required fields appearing as blank.