Thanks for the video - it was entertaining and good to see what you’re talking about 
I can’t see anything that’s obviously wrong with your hardware setup (it all looks fine), but I am curious about the following:
- In your computer’s Network Preferences, do you have more than one “Connected” network that’s configured with the 192.168.2.1 IP address?
- Does restarting QGC (instead of unplugging hardware) fix the issue?
- Are you running Companion, or BlueOS on the Raspberry Pi (onboard computer)?
- Which version are you running?
- If Companion, does changing to BlueOS fix the problem?
- If you unplug and re-plug the USB connection from your laptop, does that have the same effect as swapping the ethernet-USB adaptor with an ethernet cable and then swapping back?
- If not then my main suspicion is there may be something wrong with your USB-ethernet adaptor, although that’s a bit odd since it’s clearly working fine sometimes
- you may wish to contact support@bluerobotics.com to sort out a refund or replacement for the one you’ve got