Requiring that color management is turned off to achieve consistency is a clear indicator that your color management setup is broken. The whole point of color management is to keep things consistent.
Images must have a color profile embedded, or at least a metadata tag which describes the colorspace, otherwise the assumption most software make is that they are in the sRGB colorspace with the sRGB gamma.
I think it is too early to draw this conclusion, not least because the premise could be wrong, and because it seems to work correctly in Linux at least.
It is very difficult to figure out where your setup could be broken without being there. It could help if you uploaded a sample image. Lower the resolution to e.g. 900x900 so that we don’t have to download large files. Zip it before uploading it.
By the way, you are using Windows, right? Because RT’s preview on macOS is limited to sRGB for rotten Apple reasons.