Lately, our live theme have some very weird issue.
1. Visitors won't be counted in Shopify data or Google analytics until they add to cart or checkout. Only click here and there won't be counted. So the visitors is only 10% of normal days(we didn't change anything in campaign) but conversion rate is insanely high. Add to cart and checkout datas are right though.
2. When we switch theme to a backup theme, the problem will be solved immediately. All visitors will be counted correctly.
3. Facebook pixel not detected in Facebook pixel helper although we have Facebook pixel ID in preference. Only if we add some hard code can pixel be detected.
We still want to use current live theme since it's optimized for speed. But we have difficulty debug this issue. It's like the Facebook pixel ID and Google analytics ID in preference are not passing to this theme.