Bug with incremental and --restore?

Hello everyone,
I noticed everytime i stop ( Q ) and restore ( R ) my cudaHashcat, the new restored process start from another point, basically it skip x% of the entire process.

So i tryed a new session called X with the incremental attack (26 hours), started to stop and restore this session and the process finished in a snap
Now I wonder is a known bug or is it normal to be so? and I also wonder if there is a way to restore precisely from the point of the stop (a flag or something similar).

Thanks everyone and sorry for my english