If I visit my website first time it give me an error of Invalid form key.Please try again lator. It is giving same error while add product in the cart and it directs the page to the Home page in browser Mozilla,Safari and Chrome.
I did a following changes to resolve this issue in Admin. Store->Configuration->Advanced->System->Full Page Cache. It resolved the issue for short time.When I visit same after5-6 hours it gives me same error on the staging server.
Please specify the best solutions of this issue.