Stuck on login: Chrome

Ubuntu 20.04 LTS installed a 16GB KVM VPS.

Behind HAProxy on a PFSense box. HAProxy uses a 301 redirect from HTTP(80) to HTTPS (443). HAProxy hosts the LE certificate. There is no HTTPS enabled on the NC install itself.

Fresh NC install via snap.

When I login from Chrome/Edge, I get stuck on the “Login” Page. There is a console message of "Refused to send form data to ‘’ because it violates the following Content Security Policy directive: “form-action ‘self’”.

If I refresh, I can access and use NC just fine. I have no problems on Firefox.

Any ideas?