in a hydrous petroleum jelly product.

I've made this product for years, recently started having mold problems. Same ingredients, same suppliers, something has changed. Tried tweaking it to no avail.
I'm just a dude, as much as I research, preservatives/chemistry is not my playground.

The product is a topical ointment. Main ingredients; petroleum jelly, charcoal.
Also contains a gum oleoresin dissolved in water.

Another product, just the gum oleoresin in water (the culprit, probably), is also molding.

Scorbic acid?

I don't know who to approach with this, so I figured I'd start here. 4chan is always friendly, after all.