for 3 years now as no one solves this problem.
Topic summary
Main issue: Stores are seeing requests to monorail-edge.shopifysvc.com, triggering antivirus “untrusted certificate” warnings, 404s on the root URL, multiple requests per page load, and suspected speed/layout issues.
What it is: Shopify support repeatedly states it’s an internal, safe system tied to load balancing and Shopify Analytics, used for tests and endpoints like /v1/produce or produce_batch. The visible tag is a DNS prefetch link: (DNS prefetch = pre-resolving a domain to speed later requests).
Where it comes from: Injected via the mandatory {{ content_for_header }} snippet in theme.liquid. Not directly editable.
Workarounds and effects:
- A filter workaround can remove the specific prefetch tag (content_for_header | remove: …). Some report it “works,” but several saw worse PageSpeed/GTMetrix results after removing it and reversed the change.
- Others still report 404s and AV warnings; support suggests adding antivirus exceptions.
Current state: No official fix to stop the 404 or warnings; Shopify calls it safe and non-impactful to speed. Mixed user reports on performance and occasional layout shifts. Attachments show support chat and performance test screenshots. Discussion remains open.
4 Likes