Please
compress the hand history files from a session like this and attach them to a
Support Ticket so that we can investigate.
If the hands are in separate sessions then you can change the stake of a session using Database > Adjust Stakes.
Otherwise, you could
purge the sessions then download the hand histories from the Ignition software and import those. Because of the lack of complete accuracy in the generated Zone hands, and because the Hud can't be shown for Zone, we actually recommend disabling hand generation for Zone and instead using the downloaded hands for full accuracy.
Guide: Zone Poker