@seb321 @lydiaconwell, if it were to do with singularities, it'd have to be something like Romulan warbirds' power systems (in which case why not just use it as a general power source?) else… well, you wouldn't want it to escape containment.
Also, a quick bit of searching led to https://www.reddit.com/r/DaystromInstitute/comments/2b7poz/why_artificial_gravity_never_goes_offline/ where there's some interesting discussion of this. Some failures are mentioned.