Miranda Hart, O2 Arena

What a career arc Miranda Hart has had; from playing tiny venues at the Edinburgh Fringe in the early 2000s, followed by roles in television comedies including Hyperdrive, Lead Balloon and Not Going Out, to starring in her own sitcom, Miranda, and in the BBC One drama Call the Midwife. And now she is returning to live comedy not with a few dates in standard-size venues, but with an extensive arena tour.

Her blazing-lights-and-blaring-music entrance at the O2 for My, What I Call, Live Show (devised with creative director Thea Sharrock) is deliberately reminiscent of Beyoncé (of which more later and who herself recently played the London venue) and it's in stark contrast to the buffoonish, awkward singleton in search of a husband Hart presents herself as. There's much use of her Miranda catchphrase “such fun!” and Hart frequently deploys her trick of looking directly into the camera – relayed to the crowd on the three giant screens on stage.

The show is mostly observational comedy and Hart doesn't venture far from a well trodden route - the faces we pull when stifling a yawn, the mangled vowels of posh people and social faux pas. Much of it has a distinct whiff of recycling; I remember some of these jokes from her Fringe days and they were weak then, and even Michael McIntyre might have rejected some of Hart's material for being too bland.

The fart joke quotient is high, which explains the large number of youngsters in the audience - but if they were expecting Hart to reprise her trademark pratfalls they were to be disappointed. Instead, she punctuates the two-hour show with a series of of walks we adopt in different situations, culminating in a rather good impression of Beyoncé making an entrance on stage. Hart really is a very fine physical comic.

All comics embroider of course, but comedy has to be at some level authentic

Also punctuating the show is some well chosen music for those of a certain age (Hart mentions that she's 41 several times), leading to a couple of audience singsongs, including “I Will Survive” and Whigfield's “Saturday Night”. Her message is a joyful one – that we should allow our inner child free rein - and if ever there's another war then she should be made funster in chief to raise our collective spirit. Only a real curmudgeon wouldn't enjoy these segments.

But there's a big problem at the heart of this show; beyond Hart's bonhomie one can detect little of the real woman as she trots out one anecdote after another that one suspects bear little or no relation to the truth, whether it's peeing in front of a trainful of people after accidentally leaving the lavatory door unlocked or losing her bikini bottom in a public swimming pool. All comics embroider of course, but comedy has to be at some level authentic – either the situation it records or the emotion it provokes – and the minute the audience hears a little voice in their head saying, “Really? Really? Really did that happen?” then the game is up, and I confess for me it was very early into the show.

It's frustrating to witness, as Hart has a quick wit and what I suspect is the real her - smarter, cheekier and more sly than her stage persona – was evidenced by her interaction with the audience or in response to heckles. I really hope that if she decides to tour again she will be braver and do more personal material.

Hart is an undeniably warm performer who held the O2 in her thrall and most of the audience thoroughly enjoyed the show. But just as I thought I might be suffocated by her lack of ambition and blandness, Hart pulled a masterstroke; she left the stage as a 10-minute, tightly edited film that tied up all the show's strands in a series of well executed gags was played on the big screens. It gains the third star.

• Miranda Hart is touring until 18 October