OK
The RB input VUs show the default Windows input signal .. this is good because we now know your signal is making it that far (to the computer).

After that, it becomes a question of where RB is expecting to receive an input signal from (this is set in Options-Audio Tab-Drivers Button on the input side).

For some systems, this setting may need adjustment, especially when multiple options are available. My first thing I check is to make sure RB isn't using 'SoundMapper' or such, but rather the actual expected input. SoundMapper (and MIDIMapper) are Windows trying to make the routing adjustment for you, meaning the computer's first guess.
Many times over-riding this and assigning the expected input path in RB or PT works better. Once set and working, it should just 'stick' and work moving forward.

I do not work here, but the benefits are still awesome
Make your sound your own!