Shopify Pickup, Delivery & Shipping

[RCFerrell]

I have a Shopify store. I am having trouble with pickup, delivery & shipping apps. I've tried 2. My customers order online, and at checkout can choose how to get their stuff. Either in-person pickup, or we will deliver to them (if they live in the right area), or we ship. (We are in the US.)

For some reason I have trouble getting this to work consistently. The two apps I have tried are Zapiet and ShipZip. Both apps have great, very responsive, support. But with both apps, they work, and then they glitch in a particular way at checkout, and I'm not aware until I notice a number of abandoned carts, or one of my regular customers calls me.

Rather than go into the exact technical problem, I'm interested in how others provide the "how to get your stuff" functionality. Choosing in-person pickup, local delivery, or shipping isn't that unusual. I must be missing something obvious and/or making my life too complicated. What are some of the ways of incorporating that functionality in a Shopify store?

BTW: None of my pickup locations are shipping/fulfillment locations. We pack all orders at our main warehouse. The pickup locations are various partner businesses in the area.

TIA