Shopify Buy Button vs. Facebook Events

[benchmarq1]

Hi guys, 

we have integrated shopify´s Buy Button on our landing page (build with getresponse). When sending traffic from Facebook, not all relevant events are tracked as expected. 
We can see "Page Views" and final event "Purchase", but missing events like "Add to card" or "Adding Payment information", which happen during the check out process. 

When linking from LP to shopify product page directly (not using the Buy Button) and doing a sale, all these events were fired correctly, so the Facebook Pixel itself seems to work correctly. 

- Does the Buy Button block all events happening during the check out process?

- If not, what could be the reason? 
- If so, is there any workaround/solution for this?

Shop-URL: www.hoehlenhund.de
LP with Buy Button (at the bottom): premium.hoehlenhund.de 

Plan: shopify basic

Theme: Motion

Would be happy to get some constructive feedback. If this topic is already discussed here in the forum a) sorry and b) feel free to share the link 😉

Let me know if you need any more information from my side.  

Best regards

Benjamin