Single add to cart works but any quantity in product details fails. This is a breaking change and does not seem to be affected by Use Inventory Management setting.
This Product has a maximum order quantity of -1
Please adjust your quantity and try again.
Temporary Workaround
Adjust the field(s) in the entire products database.
Suggested Change
According to the products database max/min order quantites are new fields defaulting to NULL. If field(s) are NULL the quantity constraint(s) should not be enforced. It is unknown how min quantity behaves but min/max should not be required fields, they should only take effect when used. Note that this will affect importing products as well.