In theory, it should be a perfect match. John Morton – the man behind the brilliantly assured sitcom W1A which so gleefully skewered the BBC – gets to give us the English version of Call My Agent!: the brilliantly assured French lockdown hit which so gleefully skewered the Parisian showbusiness world. In practice, at least judging from the first two episodes, Ten Percent feels surprisingly uncertain of what kind of programme it wants to be.

At first, it looked as if we were in for a straight remake, using the same plots and characters and with the original cast replaced by British lookalikes (except, oddly, that the French agent who looked exactly like Roger Allam is played by Jack Davenport). As in the original, too, each episode features actors appearing as themselves, this time with the added advantage that we know who they are. What’s missing, though, is the glee – and with it much of the energy, bite and bracing malevolence.

This is most obvious in the celebrity cameos. Thanks to series like Extras, Episodes and The Trip, we’ve had plenty of memorable self-impersonations by the famous suggesting they’re nastier or more neurotic than we thought. Here, sad to say, they come across as thoroughly good eggs. In episode one, Kelly Macdonald was rejected from a Hollywood film for being too old: something that caused her French counterpart genuine anguish. The good-natured Kelly, however, took it pretty much in her stride. In episode two, Olivia Williams and Helena Bonham Carter’s sisterly affection wasn’t remotely affected when they were both cast in the same role.

A similar gloves-on approach applies to the agents themselves. Gone are the ruthless Gallic types prepared to fight properly dirty, and in their place come a bunch of people who only ever seem as if they’re acting tough – and not very convincingly at that.

Nor does the show’s basic sweetness leave much room for Morton’s normally invigorating satire. Now and again, we get a joke about, say, the film industry’s obsession with diversity or gender-flipping. Yet the overall impression is of fundamentally nice people doing their best. Of course, that can make for affecting television – and occasionally does here. But, in this case, it also contributes to the sense of a programme rather in conflict with its own set-up.

Meanwhile, there are signs that Morton would like to ditch his French stabilisers completely and cycle off in another direction. The one big character with no French antecedent is Simon (Tim McInnerny), a washed-up old thesp, tragically burdened with self-knowledge. Again, the unfailing sympathy with which he’s treated leads to several touching moments. Even so, it’s hard to banish the feeling that he’s wandered in from a different series entirely, and one to which Morton’s heart perhaps belongs more. Either way, Simon’s presence serves to confirm that Ten Percent is an essentially kindly portrait of showbiz life – and that this is the main problem with it.

Anybody with a moderate interest in the Tube should certainly watch Secrets of the London Underground – if only to see what an immoderate one is like. ‘Just look at this!’ began presenter Tim Dunn. ‘It’s a 1983 stock Tube car that ran on the Jubilee line!’ He then excitedly brandished a circuit-breaker switch (or something) that bears the label ‘Fleet line’, as the Jubilee was originally going to be named.

And with that, Tim joined co-presenter Siddy Holloway from the London Transport Museum to discuss what she accurately called ‘the complicated history’ of Charing Cross’s underground station. After all, not only has it had past lives as Trafalgar Square and Strand, but it was once on the Jubilee line and isn’t any more.

So where, you may – or may not – be wondering, did the Charing Cross Jubilee station go? The answer is that it’s still there, behind one of the many locked doors to which Siddy has a key and isn’t afraid to use it. (‘I’m not being funny,’ said Tim, maybe unnecessarily, ‘but this feels the same as Bond Street.’)

Rather eerily, the abandoned station has regular platform announcements and a live arrivals board – but the reason it’s kept in such immaculate condition is for use in films like Skyfall and Paddington. And from there, Siddy’s keys were rarely out of action for long as she showed us tiles from the 1890s, a construction tunnel with a bend to avoid the foundations of Nelson’s Column and any number of ventilation shafts.

Towards the end on Thursday, I did experience a somewhat guilty glazing of the eyes as yet another dimly lit tunnel was flourishingly revealed. Nonetheless, when most TV presenters are clearly faking their excitement at whatever they’re being paid to be excited about, the sight of two people so sincere in their delight proved undeniably stirring.