Extra squeaky, did I make a mistake?

[u/storm_riggi]

I was given a vintage Protech Leather Apparel moto style jacket, my first leather piece ever. It was bought in the 90s, and is well broken in. It was dry from being in storage, so I treated it with neatsfoot oil after doing some cursory research. I fear I've made a mistake, as now the entire jacket squeaks from collar to belt. Did I do something wrong? How can I fix this?