Checkout Button Disappears Once Variant Is Chosen

-- HikaShop version -- : 4.4.5
-- Joomla version -- : 3.10.3
-- PHP version -- : 7.4.27
-- Browser(s) name and version -- : Firefox 96.0.3

I notice that when a variant is chosen from the dropdown on the product display page that my Checkout button at the bottom of the right side column then disappears.

It must have been this way for a long time and I never saw it until now. You can still add to cart as normal, and then customers have been getting to checkout from the mini-cart module, but the button itself is missing.

Going to another product will return the Checkout button, but choosing any variant will remove it.

I can't see what has been done to cause this, but I track the code to the 'product/show_default.php' view, where I see this:

<?php }
	if(empty ($this->element->characteristics) || $this->params->get('characteristic_display')!='list'){ ?>
		<div id="hikashop_product_quantity_main" class="hikashop_product_quantity_main">
			<?php
			$this->row = & $this->element;
			$this->ajax = 'if(hikashopCheckChangeForm(\'item\',\'hikashop_product_form\')){ return hikashopModifyQuantity(\'' . $this->row->product_id . '\',field,1' . $form . ',\'cart\'); } else { return false; }';
			$this->setLayout('quantity');
			echo $this->loadTemplate();
			?>
			<a id="checkoutbut" class="btn" href="/checkout">Checkout</a>
		</div>
	<?php } ?>

You were exactly right. The button was missing from 'show.php'.

Once I added it to that view now the problem is solved.