Sounds like N9 arrived with a flat battery which is hardly surprising as replacements all seem to be dated 2013; but I guess you allowed it to flash with the minimum of 11% battery showing as in a hurry, whereas it really would have been better to fully charge it first as battery of this age especially if left uncharged has diminished capacity available.

Presumably kept power button depressed for at least 10 seconds, but concerned about your statement "hardware buttons are not quite usable". Is this a re-furbished device in a new housing sourced from China?

If Nokia logo stays visible device can be in a boot loop, in which case may boot up if R & D mode enabled as here:
https://talk.maemo.org/showpost.php?...56&postcount=4