pfblocker-ng don't update cron hour on update tab ?

[maba]

Hello,
Pfblockler-ng seems to brake my dns during cron update. So i try to deal with that by setting the cron job one time /day at 6h00 . i have set in pfblocker-ng/general/cron setting : once a day / 0 / 6 / 0.
When i go to update tab: i see "next scheduled cron will run at 00:00 with 5 hours remaining (in 5 hours it's not even 00:00 ...)
I have try force reload all on pfblocker-ng.
Is it normal ? how i update cron scheduling hours.

thanks ;)