I see some additional items to check.
What is your level of underway replenishment? Basic is 20% so the refuel rate would be 20,000 liters per hour. If the FF is completely empty, then Aurora may be generating the message before they can start moving and refueling.
What is the burn rate on the FF - How much fuel per hour? I doubt this is the case, but is the FF burning fuel faster than the tanker can refuel? Trying to fill the bath tub with the drain open.
Have you tried removing the movement orders and refueling at a stop? This may address the 2 problems above.
How much fuel does your tanker actually have? It will not refuel other ships below 500,000.
It is possible that in-transit refueling is still got some bugs.