“Invalid/missing blog nonce. All core actions require a valid nonce.”

I have been trying to use Jetpack with the standalone Social to have blog posts repeat out to our social media accounts.

Social refused to refresh/relink the sites, so I removed them and started over. But now I can’t add any sites at all because every request is met with this error:

“Invalid/missing blog nonce. All core actions require a valid nonce.”

I have disabled and renenabled both Jetpack and Social plugins, I have disconnected and reconnected to WordPress.com, I have logged out and back in to my account. I have tried incognito windows and other browsers. Nothing is working.

How do I solve this problem?

Thank you

The page I need help with: [log in to see the link]