Lost Connection to server, reconnecting on AWS linux

I have a new node-red running on a new AWS instance (after my 2017 was getting too old:-).

Anyway, it's working nicely, but I'm getting the lost connection to server message:

Lost connection to server, reconnecting in 54s. [Try now]

I searched this forum and see the same error. I'm not running a dashboard

I can edit nodes and deploy, but instantly it gives the lost connection error, but is deployed correctly.

Thanks.