As the video shows below, when you try to place a block and it fails, this event will signal many times at the same time, which cause great trouble to developers

Maybe only win10 players will cause this problem when using their mouse

I guess the reason is that, this signal is called in something like <GameMode::useItemOn> , but actually it is NOT a good idea to call this event here, because when you try to place a block but it is blocked by yourself or some other entity, this function will suddenly be called for many times for unknown reason.

The best solution is reconstructing the logic around this place to avoid such improper behaviors.
Or if it is too complicated, you can just add timeout limitation (about 100~200ms?) between two calls of this event. We have tried tricks like this before, and this problem will be fixed temporarily as long as the player just click their mouse ONCE to place a block.