Try adding this CSS:
@media (max-width: 480px) {
.wc-block-grid.has-4-columns .wc-block-grid__products {
display: flex;
}
.wc-block-grid.has-2-columns .wc-block-grid__product {
flex: 1 0 50%;
max-width: 50%;
padding: 0;
margin:0 0 24px
}
.wc-block-grid.has-2-columns .wc-block-grid__product:nth-child(odd) {
padding-right:8px
}
.wc-block-grid.has-2-columns .wc-block-grid__product:nth-child(2n) {
padding-left:8px
}
.wc-block-grid.has-3-columns .wc-block-grid__product {
flex: 1 0 50%;
max-width: 50%;
padding: 0;
margin:0 0 24px
}
.wc-block-grid.has-3-columns .wc-block-grid__product:nth-child(odd) {
padding-right:8px
}
.wc-block-grid.has-3-columns .wc-block-grid__product:nth-child(2n) {
padding-left:8px
}
.wc-block-grid.has-4-columns .wc-block-grid__product {
flex: 1 0 50%;
max-width: 50%;
padding: 0;
margin:0 0 24px
}
.wc-block-grid.has-4-columns .wc-block-grid__product:nth-child(odd) {
padding-right:8px
}
.wc-block-grid.has-4-columns .wc-block-grid__product:nth-child(2n) {
padding-left:8px
}
}