2013 fiesta intermittent power loss

[dj5800]

Hi Guru's,
My wife has a 2013 fiesta 1.6 litre 5 speed manual which has an intermittent issue with loss of power and hoping someone can shed some light on it.
No faults come up with the mechanics scan tool.
there is no rhyme, reason, or pattern to it.
It will just lose power whenever it feels like it.
Does not matter what gear it's in, driving around town, the power just goes away, engine still runs and then comes back of its own accord.
any suggestions?