We have a custom app that we use with Shopify POS. It has always worked fine, but as soon as POS was updated to 7.0, the app no longer works. The app watches transactions and counts when specific products are purchased. In the POS app there is a tile that displays the count for each customer. This helps us know when to give the customer other products after a certain amount of purchases. When a customer is added to the cart in POS, the tile updates to reflect the number of purchases for that customer. Since version 7.0 (and above so far), the tile just displays zero (its default state). Below is some info from our developer in a little more detail.
The issue we're having now appears on Shopify POS(We've integrated POS Cart Extension) after the POS app was upgraded automatically.
According to the documentation, it's supposed for Shopify POS to send a POST request to the "Promotions" endpoint when you add/remove a product/customer to the shopping cart. (it was working before as expected)
Our app was intended to pull data from our own database and return it when the POST request is received. so it updates the POS tile.
After the app version upgrade, it's no longer sending a POST request to the promotions endpoint.
I submitted a ticket on the community forum and Slack channel and didn't get a reply.
I've attached a screenshot to show the POS cart extension setting of our app.