SUMMARY The Tracks Table field does not show all columns separately. First two columns show merged, and 4th and subsequent columns have no values shown. STEPS TO REPRODUCE 1. File -> New Collection -> New Music Collection 2. Add Entry -> New Entry; choose Tracks tab, fill one row with Title, Artist, Length; press Save Entry 3. Collection -> Collection Fields, click Tracks field, click Set properties, choose column3 property, change value to "URL", press Set, press OK; press Apply, press OK OBSERVED RESULT The Tracks field shows two columns with with two rows, where first column combined Title and Artist with '/' delimiter: | Title / Artist | URL | | 01 | song / singer | http://someurl/ | Note that the row also adds an id column which is not shown in the header row containing the column names. EXPECTED RESULT | Title | Artist | URL | | song | singer | http://someurl/ | SOFTWARE/OS VERSIONS Linux/KDE Plasma: Fedora 35 x86_64 (available in About System) KDE Plasma Version: 5.23.3-1.fc35 Qt Version: 5.15.2-4.fc35 ADDITIONAL INFORMATION uncompressed content of tc file shows: .. <field format="1" name="track" flag="3" category="Tracks" type="8" title="Tracks> <prop> name="column1">Title</prop> <prop> name="column2">Artist</prop> <prop> name="column3">URL</prop> <prop> name="columns">3</prop> .. <entry id="1"><title>my song</title> <tracks><track> <column>song</column> <column>singer</column> <column>http://someurl/</column> </track></tracks> <id>1</id> .. I also experimented with different property names and values, deleting and adding properties, but they are not what would be exptected. I ensured the property name is columnN where N is sequential, and columns value has exact number of columns. When I add a new custom Table field, then it works perfectly as expected. It's only when modifying existing Tracks Table field that it doesn't behave as expected. The workaround is to create a new Table field, delete existing Tracks field, then rename the new Table field as Tracks.
I believe you're using the "Album" template for the Music Collection and that behavior is specific to that template. Using Default or Fancy, for example, it would show what you expect. The Album template is largely tied to the default Music Collection fields, especially for tracks, where it does expect to see a duration in the 3rd column, and then adds a total album duration in the view. The track number is just added by the view template, not in the collection data itself, as well. In addition, even with not changing the 3rd track column or adding more columns, the Album template always combines the first two. So in short, not really a bug, just behavior from the specific template. I'll see if I can make it fail more gracefully, but in the mean time, just open up the configuration and change the template for music collections.