Analytics not reporting the actual traffic

[Edgar_1]

We have a problem, that after a simple .css file change we deployed the new branch, and literally the same minute the traffic dropped 60% to what is being reported in Facebook Ads. As a result

1) Our reported traffic in Analytics dropped

2) Real traffic was the one reported in Facebook Ads service

3) the convertion rate went 2x higher, because of incorrectly reported traffic by Shopify

Our Facebook Ads campaigns went rogue, because of the incorrect CR and the spending was not appropriate. 

This has happened to us a few times in last 2 months. First we thought that maybe it's something with tools that we use (we used A/B services), but then we completely removed it and it started happening again. 

Shopify Support is not being able to answer on this and they just mentioned that there is an "ongoing investigation" and they know something about this issue. 

Anybody found any solutions?