First of all, you are sending data continuously in the main loop. have a look at this topic on Sending MQTT messages within rate limits
your code is quite bad. you don’t need to setup 2 onewire instances. you can just the sensor data by using the different index. Have a look at this tutorial https://lastminuteengineers.com/multiple-ds18b20-arduino-tutorial/ and see if you can read data from both sensors.
Once done, edit the cayenne code accordingly.