Custom HTML blocks are clipped to 150px on published storefronts

Custom HTML blocks render at full height in the Builder canvas and in Builder Preview, but on the published storefront they are capped at 150px and cut off mid-word. Because the preview looks correct, it is easy to publish a broken page without realising.

On the live store, each Custom HTML block is an iframe with sandbox=”allow-scripts” whose height resolves to 150px from CSS, and the parent page never sets an inline height on it.

Tebex injects a script into that iframe which posts {type:’tbx-custom-html-resize’, height: document.documentElement.scrollHeight} to the parent on DOMContentLoaded, and again via a ResizeObserver on document.body. Nothing on the published page appears to listen for that message.

To rule out a race condition I added my own script inside the block that re-posted the same message seven times over four seconds. The iframe stayed at 150px and no inline height was ever applied. Toggling “Remove default spacing” and “Use storefront styling” made no difference. Reproduced in two browsers at viewport widths from 800px to 2552px, on both a .tebex.store subdomain and a custom domain.

This effectively limits Custom HTML to a 150px band, which rules out using it for hero sections, feature rows, FAQs or anything else of normal section height.