I've been using free local pickup in my store for a few years and successfully added Shopify's new process for local fulfillment last month. It's worked for tons of customers. But I've had two recent problems. One shipment to Ontario, the customer wanted to add an item to his order so I told him to purchase the new item and select free local pickup and it wouldn't let him. Wanted to charge a new shipping rate and we ended up processing outside the system.
Today, a local Calgary customer wanted to select local pickup and it wouldn't let her. I had to send her a draft order and specify free shipping, but then we won't get the local fulfillment emails, etc.
Any suggestions on why it's happening so randomly?