Please try this CSS snippet
/* One column for vendor secondary attributes in a vendor block */
.hp-vendor--view-block .hp-vendor__attributes--secondary > .hp-row > div{
flex-basis: 100%;
max-width: 100%;
width: 100%;
}
/* One column for vendor primary attributes in a vendor block */
.hp-vendor--view-block .hp-vendor__attributes--primary{
display: block;
}