You are routing signal into a bus (with or without plugin), but the output routing is not as expected or not working.
In Version 10, channel types were introduced to help multi-channel panning.
If your bus has no channel type, it will not connect correctly on the bus, or not pass through the expected plugin channel.
Click in the output zone and set a channel type, the signal will connect correctly.
Same channel type menu is available in the Mixer Configure page.