How can I enable predictive search via SKU in Portland theme?

I’m trying to make it so the predictive search drawer can search via SKU. When I hard search for the product it comes up on the search page but it doesn’t come up during the search activity in the search drawer. See the pictures below.

Sadly my Java knowledge isn’t good enough to fix this.

Hopefully someone is able to help me.

Theme: Portland

I have the same issue! Any insight would be appreciated.