More information on the matter. Thoughts about the process.

First, apologies. Not sure I mentioned mod Order Delivery Date is loaded.

I've found that the option to multi-ship does not appear for PayPal as well as Square. Only money order allows the option to appear.

Regardless of payment method, the shopping cart is reacting as it should. Tells the customer that single goes to primary and multiples may be sent to multiple addresses.

With money order as the example, if only one item in the cart, it correctly does not show the multi-ship option. If more than one item in the cart, it does show the multi-ship option.

PayPal from the shopping cart page does come back for shipping but does not offer multi-ship for multiple items.

Square stays on site of course, but also does not offer multi-ship items.

Extrapolation leads to thought that whatever triggers the multi-ship option is not coming from PayPal or Square. OR... Order Delivery Date is munging something up.

It's the time of year that this site gets orders sent to multiple addresses. One car salesman sends to all who purchased this year.