USB plugs and cables can weaken over time and this can affect the stability of the Finch’s connection to the computer.
Stable as they seem, the USB cable is the most common cause for Finch connection failure. Try another USB cable and see if that fixes the problem.
USB ports (particularly on older Chromebooks) have been know to either fail, or the ports are not made to output the 5v required to power the Finch. Usually, at least 1 port on a computer will output the proper amount of power, so try other USB ports if you are having connection issues.
Often as the Finches age the connection between the cable and the USB becomes loose. Try using a cable tie or tape to fasten the USB cable to the Finch, providing strain relief, so that there is little movement of the cable near the plug.