Fix Shopify Shipping Settings

Sorry to everyone who has already responded. Our first trip here and we didn't realize that we had the option to better explain our issue.

My wife is looking for an experienced Shopify developer to troubleshoot and fix issues with her shipping settings. She wants shipping to be free to all US destinations on all existing products. She thought she had this working before, but something got messed up somewhere along the way. She is using Teelaunch (Shopify App) as her supplier/shipper. When we do a sample order right now to a known US address, we're getting a message at checkout that says "Your order cannot be shipped to this address. Change delivery address or empty cart and return to store." Doesn't seem to matter what address we pick, same alert. She has repeatedly tried contacting support at Shopify and Teelaunch and when they finally answer they both say it's the other one's problem. Free shipping seems like it should be one of the easier options, but we need help.

Key Requirements:
- Identify and resolve shipping issues
- Ensure correct FREE shipping is displayed at checkout
- Experience with Shopify's shipping settings and zones

Ideal Skills and Experience:
- Proficient in Shopify platform
- Strong understanding of shipping configurations
- Familiarity with Teelaunch would probably also be helpful
- Previous experience with similar shipping issues on Shopify

Please provide a brief overview of your relevant experience and approach to solving this issue, and if possible, an estimate of what you expect the total cost to be. Thank you.