custom icons not showing up in header on mobile

[nickrobs52]

I have custom icons in my header for the menu icon and cart icon, and neither of them show up on mobile.

I have tried the suggestions in this thread, with no luck:

https://community.shopify.com/c/shopify-discussions/custom-header-icons-don-t-show-on-mobile-devices...

In the mobile screenshot provided, I put the menu icon back to normal, so it is showing up. But the cart icon is still broken.