Hey.

I've noted the following behaviour and it seems as this could be a bug.

I recently add this release:
https://musicbrainz.org/release/c991db49-7ed2-44a0-8066-dac3fe82d73a
As you can see it consists of 2 mediums and I've also added the discIDs of both (via picard).

I now do the following (just with the physical CDs, no audio files of it):

I mount disc1, select "Lookup CD", select the (only) match in the popup and then Picard adds the whole release on the right, i.e. it shows me the entries of both discs' tracks.
So far so good, when I now select tracks from disc 1, they have the discID of disc#1 (i.e. the one I just used for the lookup)... but the all tracks from disc 2 do so either.

Even when I then mount disc2 and repeat the lookup,... there won't be any change to the above (it's still on all tracks the discID from disc1).

If I remove all the tracks (i.e. the fetched metatada) and then do everything with disc2 first, it's the same, just that the discID of all tracks will be set to that of disc2 now.

I'd rather expect the following behaviour:
If I lookup disc1, it's okay if I get all the tracks (i.e. also those of disc2), but it shouldn't set the discID for tracks from other mediums (here disc2) at all (and especially not to a wrong one), since it cannot know which of the available discIDs (if more than one) mine would have.

Cheers,
Chris.