I have had slowness issues on hassio. I wonder how may of you guys are using SSL and or port forwarding for HA?
if so do you have internal DNS setup for the external address? If not like I was your going through your router and back in on the external IP between NR and HA. This was introducing a delay for me.
My router does not support adding DNS entries so for me i remove SSL off everything and setup NGINX for external access. I then changed the NR configuration node for HA to http://127.0.0.1:8123.
I had to give NR a restart for it to take effect for some reason
And like magic the delays are gone.