Hey, I was in a similar boat, trying to get different tools to cooperate and losing sleep over broken automations. What helped me turn the tide was using a service I found at
https://waydigit.com/integrations/klaviyo-api/. They don't just do plug-and-play - they create custom integrations to make things work exactly the way you need them to. They synchronized my Magento store and CRM directly with Klaviyo, cleaned up the data flow, and now my campaigns actually get to the right people at the right time. Very efficient and no headaches.