could be an issue related to hassio not working fine: are other addons, if any, working fine / connecting to HA?
I had problems regarding nodered not connecting to HA and i solved it recreating the hassio_supervisor container ( if you have portainer is just a matter of stopping the container, click duplicate/edit icon and then click deploy ).
It could be anything else BTW, without knowing your environments and detailed logs it’s hard to point you in a direction.
About the log:
[info] [server:Home Assistant] WebSocket Connecting http://supervisor/core
make sure your home assistant is loading fine, i had this issue and the reason was a custom component ( in my case meross_cloud ): once i removed it and reboot nodered started to “talk” again with HA as soon as loaded completely.