Hello,
The display HRP state command indicates the bandwidth usage of the HRP backup channel.
But if the hrp interface command is used to configure multiple heartbeat interfaces, the backup channel usage field only displays the bandwidth usage of the heartbeat interface with the highest traffic volume.
In other words, if the secondary channel is used for other traffic than just HRP, its traffic volume might be higher and therefore its utilization will be shown in the output of the display hrp state command instead of the dedicated primary HRP backup channel.