The spy craft in me thinks it could also be a false reading to hide the drones true operational range.
That's what I would have suspected because most of the videos show the low battery message. But that would necessiate meddling with the firmware or adding something to falsify the voltage readout, which would add extra work, but maybe it would be worth it to conceal the distance to the takeoff location where probably the ground station is nearby.
Ubuntu was once an okay-ish distribution, many many years ago. Then Canonical got rogue, made some very sketchy and irritating decisions (walled garden, snap, advertisements with Amazon, now advertisements in their package manager, ...... so much more)
Ubuntu is the bane of Linux. Use upstream Debian if you like apt; Linux Mint for an easy entry; Arch, if you're quick of wits and want to widen your knowledge and skillset.