I am facing an "invalid form key. please refresh the page" when customer login and click on any add to cart button. the website on domain name and tried a lot of options like change max_input_vars values remove cookies etc. but issue not resolved. I am using a custom theme for the website. On mobile sometimes adding product to cart showing "your session has been expired".
1 Answer
Check core_config_data table in DB and make sure that web/cookie/cookie_domain is set up corretly.
If the domain of your store is domain.com then the value of web/cookie/cookie_domain should be the same.