It's not a bug. Working in RCM automatically linearizes the material in Fusion. This means that for DWG the working space becomes DWG/Linear. The Fusion viewer LUT is a simple gamut + gamma conversion without any form of display rendering applied. RCM uses DaVinciDRT by default as it's tonemapper creating the preferable colors and highlight rolloff. If you want to see this inside Fusion you'll need to unfortunately setup a custom view transform behind the MediaOut node and use that instead.
(scroll down on the images to see all settings)
CST 1: To revert the linearization and jump back to Intermediate to match the RCM working space

- Screenshot 2022-08-13 at 11.23.10.png (291.46 KiB) Viewed 543 times
CST 2: To match the output transform chosen in RCM.

- Screenshot 2022-08-13 at 11.23.30.png (374.18 KiB) Viewed 543 times
You could group these two nodes to clean it up a bit but the catch is that viewing through this means colorpicking and value reading is not in linear anymore. You'll have to turn it off temporarily when you wish to do so.
So regarding your above 1.0 values it's correct because it's linear, which is what you typically want for VFX.
Regarding the 'bug'. This has been an ongoing problem ever since the two software married and there are still no tools to work with it properly. The easy solution is to just at least give the ColorSpaceTransform as an option in the Fusion viewLUT settings or have it work automatically by reading the settings from the Color Managed settings with a dedicated entry called RCM. But who knows if they'll ever come up with something. There are dozens of thread about this issue and no acknowledgements I've ever seen from BMD or statements that they're working on improving this workflow.
It gets even worse for graphics because you don't have control over how Resolve will treat the Fusion comps so if you only use display referred data in terms of colors for things like text or motion graphics, it will still treat it as linear and render through the display transform, making it unusable for adding simple lower thirds etc.