MOBILE THUMBNAIL IMAGES TOO SMALL - HELP?

Hello - 

My product thumbnail images on my shop page used to be very large and now all of a sudden they are so tiny. Can someone PLEASE help me with this? 

22 minutes ago, happydayspickleball said:

Hello - 

My product thumbnail images on my shop page used to be very large and now all of a sudden they are so tiny. Can someone PLEASE help me with this? 

Try this:

@media only screen and (max-width:767px) {
    .products .grid-item {
        width: 100% !important;
    }
}

in the shop page code injection? 

If so, this did not work for me unfortunately 

Just now, happydayspickleball said:

in the shop page code injection? 

If so, this did not work for me unfortunately 

No, in the Custom CSS section.