Hey there,
as I understand, subtasks are also not shown in the board view of our team-managed business project and that is expected behaviour. After reading some articles I thought it should be possible for me, as a administrator of the jira instance and also the team-managed project, to use a "group by: subtask" view, but when I look at the group by menue it shows no option to group by any issue types. Why are they not shown?
Screen is in german, but I think you will get the gist of it.

Thank you for your help and greetings from germany
Conrad