The esp8266 is a complete stand alone mysensors network, it can't interact with the other unless you use a controller in between

Again, that was it! @tbowmo Thank you again so much! Everything is running smoothly :-)

I have same problem using sensebender as node and ESP8266 as wifi gateway with the sense bender node reporting HUM as a 10 digit number. Mysensors 1.5 lib and 2.0.0 ESP8266 (no diff with 2.0.3). Only affects the HUM reading - not the temp or batt voltage. Interestingly a standard mysensors DHT11 node reports HUM correctly in the gateway while simultaneously the sensebender node does not. Will try the Dev library next.