That's an interesting case alright. We had a look, and here's a summary of what's happening.
The UNREP-Out flag is set (correctly so) in the database on some of the amphibs. So they start sharing fuel among themselves and even pass it back to the tanker if the UNREP order isn't given correctly.
As a result of the orders you have given, USS Detroit (AOE-4) refuels USS Austin (LPD-4), which in turn refuels USS Iwo Jima (LPH-2), which in turn has USS Detroit (AOE-4) in refuel queue... which means you have established an UNREP closed-loop, and Iwo Jima will pass the fuel back to the AOE afterwards.
And as the refuel queues get updated, the list of who-refuels-who changes, and it gets a bit confusing to follow as fuel is passed in all directions.
It gets even worse with weapons; one or two of the ships have fired some SRBOC rounds earlier in the scenario, and so SRBOC rounds are constantly passed around to fill up whichever ship is missing some rounds.
To be frank, this situation was neither envisioned nor encountered during our development tests (timeless adage: Users will find novel and interesting ways to break a system).
There are several remedies we are considering, each with its own baggage. For example:
* Enforce a rule that only bigger ships can provide UNREP to smaller ones, unless the provider is an UNREP-dedicated vessel. This would prevent big capital ships from draining the stores of smaller ships in order to sustain themselves. The catch is you can bet we'll get flooded with requests to lift this rule "because the Iwo Jima once in November 1967 provided fuel to a destroyer that had almost run out completely" and similar edge cases.
* Prohibit ships that are being replenished from servicing other ships at the same time. This is a very sensible rule 99.9% of the time (stationkeeping against the UNREP provider is tricky enough, additionally watching out for the other guy is just asking for trouble) but again it's a safe bet we'll be presented with edge cases where this historically happened.
* Proactively check if the UNREP hookup being ordered is going to create a closed-loop situation and silently refuse to do it (if considered by the AI) or actively inform the player with a message (if it's a manual order). This requires the player's understanding of why this is happening.... and let's just stop there.
Thanks for reporting this. We'll see what we can do for the next update.
In the meantime, try to perform UNREP hookups sequentially and avoid closed-loop situations if possible.
< Message edited by Dimitris -- 12/14/2018 4:46:07 PM >