This glitch for me happened when I changed the css filters on the hover tab for the Image. For the glitch to happen you need to add rounded corners to the card. For some reason changing the css filters for the image on the hover tab causes the rounded corners effect to be removed for a split second as shown in the video above. This creates a glitchy flickering affect with the corners fo the image.
When you add this css code it fixes the problem. To get there go to Edit Posts > Advanced > Custom CSS, and then add these lines of code (Adjust the px variable in the css to the “Border Radius” you set)
border-radius: 14px 14px 0px 0px;
Now the Glitch should be fixed as shown in the picture above!