There is this little problem with permissions, that are inherit from other ranks.

Lets say, I have the groups Member, Mod and Owner and don't want, that a member can use the commands from the plugin Citizens.

I set citizens.npc.* to false for the group member.
The players of the group mod should have access to all commands, so I give them the permission luckperms.autoop and set it to true
For safety, I let Mod inherit the permission from the group Member and now comes the problem:
Even with the autoop-permission set, all players in group Mod and Owner receive the message, that they don't have the permission to use /npc.

Only after giving them the permission and set it to true, the Mods can use it.

LuckPerms should just ignore every false-perms, that are inherit form other groups, if the actual group has luckperms.autoop

No, this is intended behaviour.

If you want to override the negated permission, you need to specifically set it to true for mod.