Strange handling of identically named files - older file is showing when another identically named is dragged into PR

A friend of mine is a Lightroom user, but bought PureRaw to process some of his high ISO photos.

He told me today, that PureRaw is behaving strangely with identically named files.

File named e.g. “DSC01234.CR2” and some others from a 6D II from Folder1 was converted with PureRaw.
Now he dragged in a file named “DSC01234.CR2” from a 70D from Folder2 with a bunch of other files from that camera. Files were never processed by PR.
For files with a name already processed by PR the original files were shown. For files with unkown name to PR the new files were processed. (e.g. some bird photos within photos from a wedding).

I haven’t read about this behaviour here before, but I find it at least strange.
I use Photolab and don’t have PR to test, but if it is really like this, this annoying bug should be taken care of.
PureRaw was mostly showing the files form the other camera, but the