I have a bunch of R6 samples here (downloaded from Imaging Resource) and the CR3 raws all work fine. I think Imaging Resource used the uncompressed CR3 format: Qimage uses LibRaw so if you are storing compressed CR3's, I don't know if those are supported.
But you can turn them off if you like: use View, Include File Types, and uncheck Raw.
I have bought Qimage and the newest version behave the same.What version of LibRaw are you using in the newest Qimage? The actual version of LibRaw should support Canons R6 compressed Cr3.