comparator issue

This is not completely a bug (but is not intentional, so it could also be considered a bug, but it really is redstone behaving like normal and treating the command block as any normal opaque block), the redstone dot is acting like a cross, pointing into the command block, powering it, and the comparator is pulling the redstone signal from the command block, similar to the way a repeater would. This should be fixed, however, by making the command block success overwrite the redstone signal input of the comparator.

thank you for your help

@Kion, no. Comparators don't work like repeaters.

@Michael, the reason it's powered is because that command has been activated, which sends the block into an ON state. To deactive the command block, you need to try and activate something that won't happen or change the blockdata to SuccessCount:0