Being the voice of a reality show probably shouldn’t be the only reason to get a sitcom commissioned, else we might now be watching a starring vehicle for Peter ‘X Factor’ Dickson.

But Iain Stirling’s commentary is not only a crucial part of the winning formula that made Love Island into ITV2’s cash cow, he’s a well-established comedian in his own right. So why not?

Buffering unfortunately answers that question. For despite attracting a formidable cast of comedy names on the verge of big things, their roles are an unambitious collection of flat-sharing millennials going through predictable sitcommy motions.

Even when Stirling and his co-writer, fellow stand-up Steve Bugeja, add some emotional heft, it feels mechanical and tacked-on – mawkish even – a poor imitation of comedies that have serious themes woven into their fabric.

Taking very literally the advice to ‘write what you know’, former CBBC link man Stirling is a kids’ TV presenter called Iain who has the comically obvious flaw of not liking kids too much, slagging off the pictures they send in to his show Flummox.

He floats in that netherland between feckless youth and adult responsibility without much motivation in either direction. That may make him an identifiable type, but it means his actions don’t drive the story. Instead, things passively happen to him, and that doesn’t make him that interesting a character.

He shares his house with several others in the same demographic. The Friends ensemble may be the inspiration, but Buffering doesn’t share the writing room firepower of the US sitcom, so the drum-machine stings that cover scene changes tend to echo like a 21st Century ‘boom-tish’ rimshot after a very mildly amusing line.

The characters are broadly drawn. Jessie Cave, for instance, is their landlady, the very template of the ‘weird neighbour’ sitcom trope, even though she lives in the same house (in Bellenden Road, would you believe?). In episode one, we see her voodooing her phone as she’s convinced the ghost of her dead boss has possessed her Scrabble app. But to have that nonsense and a tragic incident that affects many people’s real lives in the same sitcom is a gear change too far.

It’s hard to see who Buffering is aimed at: the script seems too tame for the audience it will inherit from airing right after Love Island – much of episode one seeks laughs from oblique references to sex that seem anachronistically coy – while too broad and old-fashioned for those seeking something emotionally more substantial. One punchline is literally that Iain is caught with his trousers down.

There are some stronger moments, such as Ashley (Rosa Robson) and Greg (Paul G Raymond) lying back-to-back, sending each other sexts with zero intimacy, which seems an astute comment on modern relationships.

And impressive performances, too. In episode two Lolly Adefope as an unmotivated bakery teacher and Alistair Green as a sad-sack dumpee both shine – while Janine Harouni brings an appealing charisma to her regular role as Thalia, even when her storyline is no more than ‘waiting for a delivery guy to come’.

Yet having a cast that can light up the screen is no substitute for a confident script with a sense of purpose – and in Buffering, it seems this crucial element is still waiting to load.