VirtueMart 4.4.x – Checkout "Same as Billing" sends POST but no GET

[psm]

Hi everyone,

I'm running Joomla 4.4.9 with VirtueMart 4.4.x on localhost (XAMPP).
I'm trying to make the checkout work correctly — especially the "Same as Billing" checkbox. Now when I click on "Same as Billing" checkbox then whole form is cleared, because whole page is loaded.

Here's what happens:

When I click "Same as Billing", the POST request
cart.html?tmpl=component&task=checkout&redirect=0 is sent correctly (200 OK).

However, no subsequent GET request to
index.php?option=com_virtuemart&nosef=1&view=cart&task=viewJS&format=json
is made — so the page never updates dynamically.

On the official VirtueMart demo site, this GET request is always triggered right after the POST.

What I've already checked:

SEF URLs and URL Rewriting are enabled in Joomla.

.htaccess and RewriteBase are configured properly (SEF works).

Hidden menu with virtuemart and cart aliases exists.

"Use VirtueMart jQuery", "Use VirtueMart JavaScript", "Use Ajax to add/update cart", and "Enable Fancy Checkout" are all enabled.

The files vm2front.js and jquery.vmtrigger.js are missing from the Network tab (they do not load).

Plugin System – VirtueMart is enabled.

No caching or JS optimization plugins are active.

So far everything works (POST goes through), but since those JS files are not loaded, the second AJAX (GET viewJS) never happens.

Could this be caused by a missing script include, or a configuration issue in VirtueMart 4.4.x?
Any advice on what controls loading of vm2front.js and jquery.vmtrigger.js would be greatly appreciated.

Thanks a lot,

[psm]

Hello everyone,
I'd like to summarize my issue again, because my previous post was probably too long and unclear.

Problem
When I click anything that should trigger AJAX on checkout (like "Same as billing", "TOS", or quantity update), the whole checkout page reloads instead of updating only the necessary DOM part.

No JS errors in console.
Same issue both on localhost (XAMPP, PHP 8.2.12) and live hosting.

Environment
Joomla 4.4.9
VirtueMart 4.4.9 – 4.4.11 (tested)
Template: Cassiopeia (also tried default VM template)
PHP 8.2.12, MariaDB 10.4.32

Settings (screenshots below)
✅ Joomla SEO – SEF + URL Rewriting enabled
✅ VM Template – Fancybox, jQuery, Ajax for product/category = ON
✅ VM Checkout – One Page Checkout + Ajax for OPC = ON

(see screenshots below for full setup)

Tried already
Switched template (Cassiopeia / default VM
Clean Joomla + VM install – same result
Disabled cache and all extra plugins

Question
Is there any known issue with AJAX in VirtueMart 4.4.x + Joomla 4.4.9?
Could it be related to vm2front.js or jquery.vmtrigger.js not firing correctly?

Any advice or workaround would be appreciated 🙏

[Milbo]

Hello PSM,

indeed, reading the first topic I did not get the point, that any ajax fails.

The files vm2front.js and jquery.vmtrigger.js are missing from the Network tab (they do not load).

That is not a core file.

The whole case is strange. What you say reminds me at a broken ajax js. But why it sends the form then, if you do not use the button? That means first, the javascript works.

Hmmm, why do you still have the "enable legacy layouts" activated? What happens if you disable the "use shop overrides" in the "Core css styles and javascripts" section?

[psm]

Hello Milbo,
when I disable "Use current shop template overrides", it still behaves the same.

When I click for example on the "Same as Billing" button, I can see this in the console:

POST ../cart?tmpl=component&task=checkout&redirect=0

and then the whole page refreshes again instead of updating via AJAX.

[psm]

I tried also new installation of joomla and virtuemart but still the same. I do not understand it. It is on two different joomla systems on localhost and also on my hosting and different version of VM and Joomla.