When changing your theme, ensure you activate app embeds within Shopify app embeds section for the new theme. Additionally, if asset preloading was enabled in the previous theme, simply deactivate and then reactivate the feature within our app to ensure functionality in the new theme.

And If you previously had lazy loading enabled through TinyIMG on the old theme, you can activate it on the new theme, but it's crucial to create a backup of the theme beforehand.