Linked image won't actually open the link?

Hi - I have an image (the Sixt logo) set up with a link to get a quote or make a booking in a new tab but when it's clicked it doesn't do anything and I can't work out why. If I right click and select Open in New Tab, it works fine but won't just do it with a regular left click.

Must be something really stupid that I've missed but I just can't work it out. Can be found at the URL mentioned in the post.