I don't know if this counts as "authentic," but at least some of the NEO aircraft have different fuel tank configuations than their CEO cousins.
And possibly more to the point, the center tanks on NEOs use jet-ejector-venturi pumps rather than electric feed pumps.
And those pumps themselves can "suck out" dissolved or entrained vapor. Rather like a reverse version of using a hypobaric chamber to cure the "bends" in deep-divers. While at the same time sucking in more fuel though a side-port to replace the vapor.
It is also the case that the performance of the venturi pumps and resulting gravity-feed limitations/calculations may vary
per airframe. Which may be enough to explain the 5000-foot difference.
https://hursts.org.uk/airbus-nonnormal/html/ch07.html
https://encyclopedia2.thefreedictionary.com/jet+pump
Ejector Pumps are used to help ensure liquid fuel is always at the pump’s inlet, maintaining a constant flow of fuel from the pump to the tank. These make sure vapor pockets do not form, which could cause structural damage to the aircraft.
https://www.aviationsourcingsolution...s-made-simple/