Gparted live can't resize partition

Hi
Env HW:
Laptop HP 650 x64 processor with BIOS UEFI CSM (secure boot disabled)
preparing to install debin dual boot with windows
ENV Gparted-live 1.1.0-1-amd64
With windows parttioner i create two more partitions
One to backup and one to install debian
i succesfully backup win partition with partimage (run inside gparted live )
when i try to resize new debian partition with gparted live ,it opens a windows but resizing option are greyed out ...
i can't change it..
i can format it ,but i can't resize to create linux swap
i was insted able to resize the backup partition
right clicking the partition giving proble,mount is greyed out ,so it is not mounted
i'm able to resize partition with windows diskmgmt
it seems gparted live keeps it allocated in some way ...
any help will be appreciated
thanks in advance
Maurizio