Referring to the picture below, there is a signal present on the highlighted Mixer InputA channel (new to V10.0a) - in that channel there's also a Send to FX Channel (circled) , but unlike the Send in the adjacent Audio Channel 1, this send from InputA channel does not appear to actually do anything.



In the picture below, the InputA channel is muted, and there's signal in Audio1 channel - you can see the FX send works fine & there's signal on the FX channel meters, which is correct & expected behaviour.