Subtasks on Repeating Tasks in Future View are Broken

[mt-xing]

Describe the bug
Unable to check off subtasks on repeated tasks in future view.
In fact, the whole subtask system seems to be broken on repeated tasks - trying to focus a subtask results in it showing up in focus view but not updating the pin icon in future view, allowing me to click the pin icon a second time, resulting in a second copy of the same subtask showing up in focus.

To Reproduce
Have a repeated task in future view. Do not focus the task at all. Try to check off a subtask or pin the subtask to focus. Observe broken.

Screenshots

After clicking the pin icon many times:

(note the repeats inside focus)

Environment (optional)

• Browser [e.g. chrome, safari] Chrome
• OS: [e.g. macOS] Windows 10
  This is running in production.

[mt-xing]

Actually it seems like forking repeating tasks in general is broken, as I if I edit the repeating task and choose "just this instance", nothing happens.