I think there's a typo in the tank config; baseVolume is 25600 and fuel values are in total 6400:

https://cdn.discordapp.com/attachments/206472058228572162/364788286448730132/unknown.png

update:
apart from that there was a discussion to decrease value of fuel to match volume - in this case -bringing everything down to 6400. IMHO I feel that from the looks the 5m nosecone should have similar capacity to nr-12800 5m tank that is 12800. Visual comparison:

Fixed for next version