Custom font not rendering in Shopify custom theme

I have a Shopify store that a custom theme, created with Pagefly,

I am using custom fonts throughout the site, with Goodall Pro all caps for headers and Basis Grotesque Pro for body.

It looks like an update to either Shopify, Pagefly or some other software has broken this functionality, and headers are now all rendering in Times New Roman which obviously looks crap!

I have looked in Theme Settings on Shopify and the custom font is rendering on there, but not on the final version.

I've temporarily edited the theme stylesheet to change the Goodall font to Montserrat which does load OK, but this is a temporary fix.

I'm looking to get this sorted in the next 24 hours.

Screencaps attached

Long-term I am looking for someone to manage the technical side of my e-commerce store, so should this work go well I would be interested in a longer-term engagement.

Thanks

Dan