Add the environment variable ESPHOME_DASHBOARD_USE_PING=true as @finity noted above. Also documented here Frequently Asked Questions — ESPHome.
To add the variable with HA addons: ssh into your HA then open the addons.json file.
Look for "description": "ESPHome add-on for intelligently managing all your ESP8266/ESP32 devices", then append:
"environment": {
"ESPHOME_DASHBOARD_USE_PING": "true"
},
Documentation on Add-on config: Add-On Configuration | Home Assistant Developer Docs