UK Headless store displaying products excl. tax within Storefront web components

My headless site is displaying product prices excluding tax, even though this is a UK store where all prices should be tax-inclusive.

I’m entering product prices excluding tax and letting Shopify calculate tax automatically. And on the Online Store channel, this is working great.

However, on my external site using the Headless sales channel (using Storefront web components), prices show excluding tax. Tax only appears once the item is added to the cart in the cart popup and checkout.

Is this expected behaviour with the Storefront web components?

I’ve tested toggling “prices include tax” in settings, but that breaks the Online Store pricing (as expected) and makes it behave the same as Headless.