Instruments included in an InstrumentGroup by a <ref> loose their names

I am attempting to bring the documentation for the instruments file up to date (V3.5). I have found a number of problems that may be of no importance. Each is being reported as a separate ticket.
The old documentation states
"* ref
The id of an Instrument previously defined. The Instrument will be added to this InstrumentGroup on addition to the group it belongs."

Nearly! The instrument appears as a blank line in the instrument list for the instrument group.

1 Set instruments list 1 to RefInInstrumentGroup.xml

2 Clear instruments list 2
3 Restart MuseScore
4 Start a new score and select the Odds instrument group in the instrument list
There are three blank lines in the drop down menu
5 Select each blank line in turn and add the instrument to the score.
The score looks fine, except that the three different instrument names are followed by 1, 2 and three, as if they were all the same instrument

The stave properties look fine except that the part names are just 1, 2 and three.
(If you add only one of the instruments to the score, the stave label is OK and the part name is blank.)

Using trackName makes no difference - it is still blank in the menu.