Quantity adjustment in shopping basket not possible for custom line item

Hello everyone,

I have noticed that I cannot adjust the quantity in the shopping basket for a custom line item. When I adjust the quantity, I get the message:

Unfortunately, something went wrong.

At first I thought that I had configured the custom line item incorrectly, but I would be surprised if I had. To test this, I copied all the properties of another product for which the quantity adjustment works:

$cart = $this->cartService->getCart($context->getToken(), $context);
$first = $cart->getLineItems()->first();

However, the quantity adjustment does not work.

What could be the problem?


Any idea what’s the problem here?