Hi Cube,
Unfortunately, I don't have much more idea to suggest...
Or, maybe this little one : Try to use the HIDSerialMonitor client provided in this package https://github.com/rayshobby/hid-serial.
(When I experimented HID on my Linux host to write Kernel Driver, I've used that tool to do diagnostics)
You can also compare its firmware implementation with your, or even try the "Hello World" example by tweaking the usbconfig.h to match your hardware and see if the disconnect problem still there.
BTW, what "dmesg" reports on your Linux machine ? Are the "disconnect/reconnect" messages shown there also ?
Unfortunately, I don't have much more idea to suggest...
Or, maybe this little one : Try to use the HIDSerialMonitor client provided in this package https://github.com/rayshobby/hid-serial.
(When I experimented HID on my Linux host to write Kernel Driver, I've used that tool to do diagnostics)
You can also compare its firmware implementation with your, or even try the "Hello World" example by tweaking the usbconfig.h to match your hardware and see if the disconnect problem still there.
BTW, what "dmesg" reports on your Linux machine ? Are the "disconnect/reconnect" messages shown there also ?