1. Create a new project, simple everything, and a scrum board. Enable time tracking on the board.
2. Create a new field configuration
3. Hide the Time Tracking field in the new field config
4. Make a new field config scheme and apply the field configuration to subtasks only
5. Create an issue, and a subtask for it
6. Try and view it in the issue details pane of the work board.
If you deminify, then you get something like:
Which points to:
Unhide the Time Tracking field in your field configuration.
We should either throw a usable error message that an end user or admin can action on, or handle it somehow.