Hello

I still didn't figure it out exactly, what is the issue with LGT8F328P and arduino, but for start, it can work, if you define 4x faster baud rate. So I define MY_BAUD_RATE 76800 and connect terminal with 19200, and it works. LGT is started in 8 MHz by default, and it looks like this is not corrected with mysensors. But this only helped for serial port, because later I had issues with DHT library timings.

If I later change speed to 16 MHz and start serial port again, it works as expected:

noInterrupts();
CLKPR = 0x80;
CLKPR = 0x01;
interrupts();
Serial.begin(19200);