Mqtt auto discovery 2nd device

Hi All
I am a newbie to this stuff and still learning, I have Hassio IO running on a PI and have various devices around my home from Tuya, Mqtt, ESP, and more. I have recently added a second MQTT device a Sonoff TH10 to monitor the temp in my aquarium and control the lights. I have successfully re-flashed the Sonoff and have it connecting to the PI. I can see this in the logs for the Mosquito MQTT broker add on. For the life of me I can not get this device to auto discover. I already had an Mqtt device that once I set up auto discovered. I have even uninstalled the Mosquito add on and re installed, it searched and found the original device but not the new one. I have MQTT configured in config/integrations/dashboard and this is where I can see the existing device but can not see the new device. Any assistance on this would be great.

Using Tasmota?

Have you SetOption19 = 1 ?

Have you used mqtt explorer to view the homeassistant topic?

Thanks I knew I was missing a step much appreciated
That was it