Custom Metadata for Hierarchical type entries deletes existing entries

[ChrisMillward]

I have a column called Subjects, 'comma separated text, like tags' and it is Hierarchical like Genre. Levels are dot separated, e.g. Microscopy.Electron
On selecting 'Custom Metadata' any existing subjects are displayed in the box and the drop down list will show other existing subject entries.

Choosing one to ADD will overwrite all existing entries leaving only the new entry. For example, if I have 'Microscopy.Electron' (as actually presented in the Subjects box) and I select 'Article' from the list, I end up with just 'Article,'. Unfortunately this went unnoticed for a while leaving many disparate subjects just as 'Article' instead of 'Microscopy.Electron, Article'.

The reason for this behaviour is the lack of a comma when the custom data is first displayed. Manually adding a comma (Microscopy.Electron,) allows the new subjects to be added properly Each subsequent new entry IS entered with a comma terminator so you can ADD further subjects without a problem.

Presumably this also applies to other hierarchical Columns like Genre.