The ‘A’ in Affirm on website has empty blue box behind it on product listing

As the title says, the ‘A’ on the site I’m working on, has an empty blue box behind it. It was recently developed(in Magento) and the developers say it’s an issue with GTM being on the site, and that removing GTM would fix it. As I’d like to keep GTM on the site, I don’t know why having this would cause the issue of a blue box behind the A. Has anyone else experienced this? You can see an example here. https://www.dkcustomproducts.com/complete-hiflow-828-air-cleaner-milwaukee-eight-naked-no-cover.htm It’s in the area underneath price for the item