PPFunnels requires app proxy url as "/a/s", verify if any app occupies "/a/s".
How would I know my app proxy URL?
1. in Shopify Apps > app > "View details"
2. A pop up window will appear. Scroll down to the bottom the see the App Proxy URL. This time it is /a/s/
3. If Intercart app proxy URL is not "/a/s", find & modify the other app using app proxy "/a/s"; then update app proxy URL to "/a/s"