RCM Linear transformation bug?

hi,
come across something weird - if I set up RCM with Alexa input, Linear Timeline and Rec709 output, then the result is different (whether working with graded images or not) to if I check the 'Use Separate Color Space and Gamma' box, which shows the timeline as being Rec709 colour space with Linear gamma.
It seems as if there is no colour space transformation occurring anywhere at all, only gamma curve transforms. Is this normal when working with Linear?
come across something weird - if I set up RCM with Alexa input, Linear Timeline and Rec709 output, then the result is different (whether working with graded images or not) to if I check the 'Use Separate Color Space and Gamma' box, which shows the timeline as being Rec709 colour space with Linear gamma.
It seems as if there is no colour space transformation occurring anywhere at all, only gamma curve transforms. Is this normal when working with Linear?