This might be a Redshift issue but I noticed that when using the Position Object operator > Density By Texture feature, that the channel selection (Ambient, Diffuse etc) doesn't seem to match between Redshift vs Standard/Legacy Materials. This can be kind of confusing behaviour.
So:
In Legacy Material > #1 Diffuse = #1 Diffuse (tyflow)
In RS Material > #1 Diffuse = #0 Ambient (tyflow)
Video attached.
So:
In Legacy Material > #1 Diffuse = #1 Diffuse (tyflow)
In RS Material > #1 Diffuse = #0 Ambient (tyflow)
Video attached.