"Submit cluster as release" currently submits tracks in order of the cluster. For automatically created clusters these are ordered by track number. If tracks get manually added the order can be different.

"Submit cluster as release" should always use order given by disc and track number order (if set).

It should also be investigated whether cluster tracks should always be resorted if new tracks get added to the cluster manually.

See discussion on https://community.metabrainz.org/t/confusing-picard-submit-cluster-as-a-release-scrambles-order-depending-on-how-items-are-dropped-into-the-cluster/676828/