VAGfan

The Macan dash display of boost is "Gauge" pressure, what you see on a scan-tool is "absolute" pressure.
Normally, "Boost" is referring to Gauge pressure, how much more pressure the turbo is generating above atmospheric pressure.
So, 2.2 bar absolute is 1.2 gauge, which equals about 17PSI of boost.

Interestingly, I also own a 2024 VW Jetta GLI (no tuning mods), with a variant of the same 2.0 EA888 Gen3+ engine, and it makes more boost, about 20 psi. But it is rated at only "228 HP"...VW/Audi/Porsche do some marketing manipulation of the rated HP of many of their engines, often lowering the published rating on lower priced applications of the same engine....The EA888 Gen3+ engine, in my 2019 Macan, was rated at 248 HP.

DHL

Manifold pressure should be cited in pressure absolute as opposed to gage because you can have a vacuum condition which would result in negative readings in gage pressure. I know we are talking about "boost" pressure, but that is actually a subset of manifold pressure. Re the differences with VW and Porsche, 20 HP is less than 10% and you might get that as typical manufacturing tolerance within a run of vehicles. Timing differences could make a difference in max HP even with higher boost pressure.