There has been a few updates to the RED SDK since the last few releases of 14 which likely attributes to the issue. Generally the SDK itself handles all the debayer math for R3D files. I suggest trying a current build of RedCineX and see if you have the same issue. If not then it can be narrowed back to Resolve. Premiere does not update to the newest SDK as often, and as such may not have this issue
Thanks for your answer, so with Redcine X 50.5.0, I haven't the problem :
But problem is my Resolve version (15) come to App Store, and I can't downgrade to Resolve 14 It's a Resolve Studio. Maybe I should update something, like r3D codec, or other ?