Browsers suddenly blocking my shop domain name for invalid certificate

Topic summary

Shop visitors see SSL/security warnings on custom domains, especially on the www subdomain. Firefox reports HSTS (forces HTTPS, no exceptions) and SSL_ERROR_BAD_CERT_DOMAIN showing a certificate valid only for *.myshopify.com.

Primary case (magsrags.net):

  • Symptoms: www.magsrags.net blocked (Firefox), root magsrags.net loads; initially Edge also warned, later Edge allowed access.
  • Diagnosis: A record correct (23.227.38.74). CNAME for www was set to magsrags.myshopify.com but should be shops.myshopify.com (Shopify standard).
  • Actions: Merchant updated CNAME at GoDaddy; issue briefly resolved, then returned in Firefox. Advised to contact Shopify Support for deeper account-level review after DNS propagation (up to 48 hours).

Secondary case (percnt.com):

  • Symptoms: Some customers (UK) get “certificate not trusted,” especially coming from Instagram and on 4G/mobile data. Works on Wi‑Fi and for users in other regions (e.g., Canada).
  • Checks: DNS correctly points to Shopify. No obvious misconfiguration.
  • Next steps: Verify with GoDaddy that certificates are correct; rule out link shorteners; consider carrier/network issues; contact Shopify Support to confirm backend domain/SSL status. Screenshots from customers are relevant evidence.

Status: No confirmed resolution yet. Key tasks are ensuring www CNAME = shops.myshopify.com, allowing propagation, and escalating to Shopify/GoDaddy and possibly mobile carriers if issues persist.

Summarized with AI on December 23. AI used: gpt-5.

With domain issues it’s hard to know exactly where the issue is coming from unless it’s a straight forward one like your A record is pointed to the wrong address. That would be a simple fix, but with this you want to rule out all options until you narrow down what the issue is exactly.

It looks like this is a location based error, but you should still contact GoDaddy just to rule out that there are any issues on their end. I tested your website on my laptop and phone, using Wifi and my data and I had no issues or warnings, but I’m located In Canada so the issue doesn’t seem to be affecting me.

After you speak with GoDaddy if there is no issue on their end I would contact your service provider to ask if there have been any outages or issues recently.