it's possible for your firmware to cause the device's USB connection to become unresponsive if for example you have a very busy loop() function. try repeatedly flashing a blank / minimal, known-safe app and see if it behaves differently. if you see the same problematic behavior, here's the standard troubleshooting steps and info we need to help:
in addition to the info listed there, please share the Device OS version your Particle device is currently running and whether or not you are attempting to upgrade / downgrade.