The quality filter is already blocking "problem" in question title on Stack Overflow. All good and running well for long time.
However it does allow the word "problems" and honestly, can't see the point in this.
Quick search for "problems" in question title revealed it's not hunderds, maybe around 20-30 every day but still, would like even those to be titled properly.
Either block both forms of the word or remove this filter altogether.