Clear button is a WooCommerce functionality and our theme shouldn’t influence it. We ask you to install the 5.3 version temporarily because you said it worked before. That is why we would like to see how it works in order to understand what change in the 6.0 update causes the problem now.
Download our 5.3 version here https://drive.google.com/file/d/1ZF9zIimd0l6-bgFCXcEdzJMY0yBUL99k/view