Publish buttons (Save Draft, Preview, and Publish) are greyed out

Hello,
I am using WordPress 4.2.4 running Twenty Fourteen theme. I have a problem where the publish buttons (Save Draft, Preview, and Publish) all get greyed out / unclickable after about 3 minutes of editing a new post. Seems whenever i make changes to the content of the post these buttons become unavailable to click on making it difficult to save drafts and publish new posts. I have a few plugins enabled perhaps I should try uninstalling them first?

Can this have to do with me being behind a VPN ? I recently purchased a subscription to ExpressVPN for security reasons. I am wondering if it has something to do with DNS redirection?

Thanks a lot for your help.

Regards,
Mike