Where are the voidstones after Migration?

Hello GGG,

After Migration it seems the voidstones are gone.
The game does say "Obtained" but they are gone, i can't find them in the stashtab either nor under hidden stash tabs.

I noticed that after killing Exarch again, the voidstone dropped again.
Not a problem but is this a oversight? Migrate ALL doesn't seem to be migrating ALL.

Talk to Kirac in your hideout.