Magento cookies can conflict when a user tries to log in on a subdomain instance due to how cookies are handled in relation to domains and subdomains. Here’s a detailed explanation of why this conflict occurs:
- Domain Scope of Cookies:
- Cookies set on a main domain (e.g., example.com) can be accessible to all its subdomains (e.g., sub.example.com).
- Cookies set on a subdomain (e.g., sub.example.com) are not accessible to the main domain (example.com) or other sibling subdomains (another.sub.example.com).
- Magento Cookie Settings:
- Magento uses cookies to store session data, user preferences, and authentication tokens.
- If Magento is not configured correctly to handle cookies across different subdomains, conflicts can arise.