Magento2 – Not able to refresh the cache from admin

I experiencing for quite some time.
While I can clear the cache from console, but from admin when I hit refresh, the cache is still showing as invalidated.
when I navigate to other page – it says for example two cache is refreshed. but when I check the cache page – it still shows invalidated.

I tried changing permission for var directory to 755 from 777 and back with no luck.
the directory ownership is fine and owned by the web-user.