WooCommerce dropdown cart plugin causes glitch on page load

I’ve been building this site using a custom theme. I have installed woocommerce and added an extension that allows the cart to display as a drop down menu.

The problem is every time a new page loads the basket dropdown opens for a second causing a glitch. Also if I’m logged in the WP admin bar disappears at the same time as the basket glitch.

Can anybody help me with this issue please.