Those official figures are about the same as mine (3 lt diesel XF) but I go get slightly higher than you in the real world, average on the iphone app is currently at 36.2, but I do 25 miles each way, through town onto 15 miles of the M1 (normally cruise set at 75mph) then through town again at the other end.
Around town dashboard tells me 32, on motorway low 40’s.
When I first got it it was much lower, although was assured that there is no longer a recognised “breaking in period” so was not put down to that. The dealer plugged it in at 5K and reloaded the mappings which picked up around 4 mpg from that point on. Could pay to check with dealer if they have similar issues?
Also add in a bit of “new car madness” which didnt help initially, I now tend to upshift earlier around town (when I can be bothered) which seems to help (premise being with such a low torque peak may as well stay at low revs).
Other thing that helped was going from a set of made of cheese Pirellis to dunlop sports, again added approx 2-3 on average.
And the above is not driving like a Nana the majority of the time.