Loading frontend child product results in empty page until page is reloaded

[Thomas Kampp]

I think I have found the problem. It turns out that if you add "related products" to a multi variant products with child products, then it stops working. So simply remove the related products and it works again it seems.
This must be a bug, but I am not sure where to report it.

[MarioP]

I described my problem in here :https://forum.virtuemart.net/index.php?topic=146237.msg520083#msg520083 and after further investigation I can only confirm:

I think I have found the problem. It turns out that if you add "related products" to a multi variant products with child products, then it stops working.

The same happens to me. But this is definitely not a solution:

So simply remove the related products and it works again it seems.

What's worse I'm not able to reproduce the issue on the VM demo site - adding a related product to a multi variant doesn't result in a page with only that product visible after the update (which happens in my case).
--
Where I can find the code that prepares response for the Ajax call?
'tmpl=component&format=html&dynamic=1'
For me ajax gives two different responses (depending I use the related product or not).
This is the response when a related product is added  - actually the related product itselves 

Code Select Expand

<div class="vm-product-media-container"><a href="/wcdmc/en/products-en/accessories/stands/stand-detail" title="Speaker stand" target="_blank">Aluminium speaker stand</a></div>
That's why we have that incomplete website after the dynamic update, but what is the reason?