Revert the mod 'chance to drop' to 'always drops' until you re-release mods.

This is simple:

By reducing the drop rate to 'chance to drop' so soon, you are just widening the gap between the haves and have-nots, this move is being universally derided in the forums (or almost).

I think that you should have saved this change of mechanics to after you rebalance the mods.
Rollback mods to always drop, so players can up their game in the current scenario.

Let this change roll back in after you rework the mod attributes. New mod power levels, new drop rates.