That's the max rate of the Chobham 805E Fuselage hose drum unit - it may just be a problem dialing it back to the approx. 1500l/min fighters can accept fuel at.
The HDU wing 905E pods deliver fuel at the same rate the older pods Chobham have been building for 40 years and it's hard to see Tornados taking fuel from Victors and VC-10s for all that time and suddenly developing a problem with the new tanker.
Is that the same Chobham that developed the explosive armor plating for tanks?