Admin Area Issue

I have an issue with my admin area and not sure how to fix it.

I login and it fails. All information is correct. This is the same for all my team. This also occurs on all browsers.

However, if we check the Remember me box it then logs us in just fine. Obviously, we don't want to be constantly logged in for Privacy reason. Have you come across this issue before or any ideas on how to fix it.

Thanks.