Chest-access problem with WorldGuard

Hello,
I have big problem with WorldGuard, owners of region can't access their chest. I want to set this that strangers can't open chest but owners can access it. I used command like: "/region flag miasto1 chest-access deny" and then "./region flag miasto1 chest-access -g owners allow" and it didn't work. I have to say that it worked with "build" flag. Please help me with that