When you replaced that damaged blade, did you check the balance? From your description I don't think you bent anything.

I find a significant difference in weight in the blades. I use a micro scale (very cheap on eBay) to weigh them, and aluminum foil tape or gaffers tape to match them, writing the weight on the underside of the blade for reference. You can also remove both blades from the head, attach them to each other, and check the balance over a small round object, such as a round pencil. Add tape to the lighter one to match them.

They really need both static (weight) and dynamic balance to make it fly really smooth; this takes practice in where to apply the tape.

When I purchase a set of blades I balance the lot ahead of time so they are all matched to the heaviest one. Upper blades do not weigh the same as lower.

William