Getting the exact same thing.
Using the provided script “ArduinoTypesExample”.
It works on the Serial Monitor on the IDE if I type in “lines”, but getting nothing on the UE editor. Lines comes out as blank, Float as 0.0 and Integer as 0.
I know the Arduino to UE communication is working, because I made a light turn on/off with a button using this example : https://www.arduino.cc/en/Tutorial/DigitalReadSerial
What I did notice is that typing the commands on the Serial Monitor only works if “No line ending” is selected, the other options return nothing. Could this be the issue since there is option for that in the “Write LIne End” in Blueprint?