I had a full stocked Water tank on my vehicle with an RV Kitchen attached. I had stuff in it so I hit no for the pick up items, and then yes for the fill up container, but realized after I’d done it that my canteen was already full, selected it anyway, and then yes for a drink. My water tank went from 100% to 0%.
IIRC this should be fixed in the experimental already. Thanks for reporting it though!
I figure about half the stuff I report is fixed in experimental. 
Does this mean it is not fixed in the GDI version?
No it should be, but only if you are downloading the experimental, not the stable version.