You are using the third-party plugin YITH WooCommerce Product Add-ons Premium plugin to add the additional options but plugin does not display them on the grid and it causes issue with adding product to cart. If you plan to use this plugin I would recommend you to disable swatches on the grid http://prntscr.com/oonip4 or submit additional customization request here to add compatibility of variation swatches with that third-party plugin because additional customization is not included in our support. Also, I would recommend you to contact plugin author to fix the Warning after adding to cart https://prnt.sc/oongek
