Purchase event fall into unassigned traffic Recently I found my GA4 purchase data all fall into unassigned, I am using shopify, all GA4 data before is fine. One day I found that all GA4 purchase data fall into unassigned traffic. I figure out the reason may be the user ID has some wired variable, append wired ID All user id append @^_ with user ID, I don't know how to fix this issue, I didn't change any store configure or GA4 setting. Is someone face and solve this problem before under shopify and GA4? I am looking for someone can share how to fix the problem.