"troubling fact" is correct and usable in written English.
You can use it to describe something that is concerning or alarming. For example: "The most troubling fact about the situation is that we have no idea how to fix it."
Growing inequality, stubborn pockets of immobility, rising rates of deadly addiction, the increasing and troubling fact that where you start determines where you end up, heightening political strife--these are the disturbing realities threatening ordinary American lives today.
Samsung's media arm continues code red damage control in the wake of the latest report surrounding a faulty Galaxy Note 7. The incident, which occurred on a Southwest flight earlier this week, further complicates the matters for several reasons beyond the already troubling fact that it played out on a plane – which, thankfully, was still at the gate.
But behind the opulence lurks a troubling fact.
But behind my nerves is a real and troubling fact.
In fact, Casalotti's case reveals a troubling fact of the bone marrow register: a dearth of donors for ethnic minorities.
Perhaps the most troubling fact of all is that the bill will do very little to reduce systemic risk.
Snopes (bless them) went to even more trouble fact-checking Neon Nettle's extremely sloppy fake sleuthing.
Equally troubling was the fact that the Keynesian economics practiced by many governments seemed to lose its effectiveness.
Equally troubling is the fact that, among students experiencing depressive symptoms, only 16% seek psychiatric treatment.
Also troubling is the fact that these commercials reflect a cultural confusion about what to do with dads.
Equally troubling is the fact that 17% of the articles did not mention any source for the information presented.
