Estimated Time of Arrivals and Distances

My understanding is that the ETA times given are from a point on it's last status change and doesn't update real time on it's current location. I believe this is intended to reduce server load and delay when you have the units appear in the list and then filter by who is closest (you may notice sometimes after a second or two they don't sort in the correct order straight away due to there usually being a slight server load).

Additionally the ETA given is obtained from a function on Open Street Maps that provides this but can sometimes be slightly different to what the actual route duration is (again more of an issue with OSM). The more accurate route timings would take longer to obtain and if you have, like me, 100+ vehicles that's a lot of routing to calculate!

As such I wouldn't say it's a bug, just an issue that arises from how the game is optimised unfortunately.