So, now I have the same problem with a 5V pro clone.
With normal bootloader:
the board gets stuck in a loop with flashing LED when i try to reboot it.
With MYSBootloader (1.3.0-beta.4 or 1.3.0-beta.3):
unable to upload a new sketch using the FTDI cable
node doesn't seem to get recognized properly by the GW or the controller. I see it's contiously sending "mysensors-out/10/255/4/0/0 FFFFFFFFFFFFFE400102" messages on MQTT, which I think is when it's checking for a new firmware, but nothing on the serial monitor. This makes it impossible to upload a new sketch OTA.
Any ideas on how to troubleshoot?