ESP32 not playing well with MQTT?

Third party integrations
1

Hi,
im trying to integrate a custom sensor with an ESP32 chip via mosquito MQTT.
Im already using another non esp based sensor with MQTT that works really well.

However now im getting " Attempting MQTT connection…failed, rc=-2 try again in 5 seconds"
This appears to be a common error, however I havent found many ideas on what to do about it.

I found this ESP32 MQTT error - Internet of Things Stack Exchange which makes sense, because the esp is not on the same pc while the working on is, but im not sure how to fix it in the mqtt config.

Any pointers?