Checkout card form missing with Combine JavaScript

If you enable Combine JavaScript in SiteGround Speed Optimizer, the card form on your checkout page can disappear.

Why this happens. Payment provider scripts (Guesty Pay and Stripe) must load directly from their own domains. They break when they are bundled into a combined JavaScript file.

How to fix it.

1. In SiteGround Speed Optimizer, go to Frontend Optimization > JavaScript.
2. Add the payment script handles to the Exclude from JavaScript Combination list. For Guesty Pay, exclude the handle guestypay and the path pay.guesty.com. For Stripe, exclude the handle stripe-v3 and the path js.stripe.com.
3. If you also have Defer render-blocking JavaScript enabled, add the same handles to its exclusion list.
4. Save your settings and purge the Speed Optimizer cache.
5. Test the checkout page in a private browser window while logged out.

With these exclusions in place, Combine JavaScript and Defer can stay enabled and the card form renders correctly on checkout. Test while logged out because the optimizer skips logged-in page views, so the problem does not appear when you test from wp-admin.

If you prefer, contact support to have a small plugin installed that applies these exclusions automatically.

Still stuck? Contact the HomeRunner team with your site address and what you tried, and we take it from there.