RAK4631 COM Port suddenly not working

[jpms (John Perloe Sotto)]

Hi! Here is the information about the issue. I was hoping you can help me. Thanks!

• What product do you wish to discuss? RAK4631, RAK3372, RAK11200, RAK11310, RAK11722?
  RAK 4631

• What firmware are you using? (RUI3 or Arduino BSP or other IDE (e.g. STM32CubeIDE)?
  I believe this is Arduino BSP.
  I am using Platform IO in configured in Arduino Framework

• What firmware version? Can it be obtained with AT+VER=?
  Not sure. Haven’t checked and I cannot check now that my device is unusable.

• Computer OS? (MacOS, Linux, Windows)
  Windows

• What Computer OS version?
  Windows 10 enterprise but I can confirm that it gives the same symptoms when I connect it to other PCs.

• How often does the problem happen?
  every time since running the unit test in this link:
  https://github.com/jpsotto/RAK_unity/tree/main/test/test_embedded

• How can we replicate the problem?
  Please try loading the repo link above and run it in platformIO.

MAIN ISSUE:
I was trying to learn unity unit testing when RAK4631 COM Port suddenly stopped working after running my basic unit test.

[beegee (Bernd Giesecke)]

Never used Unity Unit Testing, not sure what UNITY_BEGIN(); and UNITY_END(); are doing.

Without testing, just looking into your test code, it is running the loop without any delay() function. Most likely the device is not even able to do anything in this configuration.

Try to double push the reset button quickly to force bootloader mode while connected to your computer.
The device should show up as a new external drive with the name RAK4631. From that point, you can try to flash a different firmware.

[jpms (John Perloe Sotto)]

That was fast! The double push of the reset button did the trick.
I got it working again.^^

Thank you so much Bernd!