Hi @miemie ,
I set the setting you mentioned to prevent people increase quantity.
Fixed the problem right away.
But it would be better the system will check if quantity is valid after changed quantity by customer.
For example, I added one A which have set B as frequently bought together item (maximum 1). If I changed A quantity to 2 in cart page, B should be also can be change to 2. etc.
Ax1 -> Bx1
Ax2 -> Bx2
Thank you. ?