Hello, something I just realised! I have let say 1000 pundix

Question

Hello, something I just realised! I have let say 1000 pundix

delegating in pool A
I have 2000 purse in my reward.

I got an extra 20 pundix to delegate
I delegating them in Pool A too

Instead to combine them all:
So: 1000+ 20= 1020 pundix total

They will automatically restart all from fresh :( 😞

Is there a way to avoid that?
I don't want to claim the reward yet just wanted to add more Pundix in my same validator.

Is this a bug?

Thanks to let me know @BluStitch or any @admin