The same album appears more than once

If you have the same album in more than one format, or the same library served by two servers, you will see it more than once until version grouping collapses them.

Settings → Display → Album Version Grouping turns that on. Serento then shows one representative per group in the lists and keeps the rest one tap away.

Reaching the other versions does not depend on that setting. Open any album and, if sibling releases exist in your library, a Versions section appears on its screen with the alternatives as tiles, plus View All when there are more than fit. The album's ⋯ menu has an Other Versions item that leads to the same place. Both are there whether grouping is on or off.

To choose which one represents the group, open the ⋯ menu on a tile inside that Versions list and pick Make this the main version. That one does need Album Version Grouping to be on: with it off the item is greyed out, because there is no collapsed group for a main version to lead.

On a large library, flipping the setting is not instant: the grouping is recomputed and re-stamped across the whole catalogue, which takes time proportional to its size. The lists update themselves when that finishes, so you do not need to restart the app.

Grouping matches on the release itself, not on the file path, so the same album in FLAC and in DSD collapses into one entry with both versions available.