Sounds like your focus has degraded. Did you have to increase the power recently, and did the problem occur then? A poor focus will cause a broader, shallower weld with poor penetration. Operators will compensate by upping the laser power. Higher powers will often cause material ejection from...
Have you considered brazing? It may require some modifications to your part so that you can fixture it properly, but the elimination of the secondary finishing operations might pay for the additional expense.
