Teensyduino 1.51 Upload constantly fails, Ubuntu 18.04, Teensy 3.6, Odroid XU-4

Hello,

I am trying to upload sketches to my Teensy 3.6 using Arduino 1.8.12 but the teensyduino uploader consistently fails after the first upload. When I upload, the teensy loader app greys out and become unresponsive. The error messages are along the lines of:

1. "Unable to configure Teensy Loader to Auto mode! This error should never happen (when using Arduino) ..."
2. Pop up says: "Teensy is not repsonding", and it gives me the option to force quit
3. "Error reading Teensy Loader Status! ..."
4. "teensy loader is currently busy with another operation"

I have removed modem manger, installed the linux udev/rules49 file, and am uploading to a simple blink sketch from the examples list to "Teensy 3.6 on /dev/ttyACM0". It is curious that I am able to upload once after a reboot to the Odroid XU-4, but am unable to upload after the first sketch.

Any help would be greatly appreciated

Update: I was able to improve the upload performance by installing the Ubuntu loader app from: https://www.pjrc.com/teensy/loader_linux.html. I had to install the Raspberry Pi program, as that was the only one that worked for the Odroid XU-4.

However, the loader app still crashes frequently and I find that the serial monitor crashes whenever it is opened. The serial monitor crashing happens regardless of the delay that I insert into my code.