My Torch 9850 had the same issue. Usually a battery pull would fix it. When it didn't I would keep it plugged in and would notice that eventually the lightning bolt would come back on. For other reasons, I needed to do a clean wipe of my phone a couple times in a row, ultimately not re-installing all my apps. I found that the charging issue was resolved after omitting a certain APP. Once I updated my OS it didn't happen anymore either.
Good Luck!!
Might help the OP if you could remember which app it was.