Send Checkbox Doesn't Update Visually In UI After Save

This issue affects Webforms 7.x-4.12 & 7.x-4.13, I haven't tested other versions.

When updating the notification emails (E-mails tab of Webform), the checkboxes that enable/disable the notification revert to the previous value after save. This appears to be a UI issue (visual), which is why I've marked the component as User interface. The actual saved value (checked vs unchecked) seems to be saved correctly.

Steps To Reproduce

1. Setup or edit an existing Webform.
2. Click the E-mails tab.
3. Add at least 2 entries, be sure to save.
4. Click (to uncheck) one of the entries.
5. Click save. Notice that after the save, the checkbox appears as checked.

Additional Notes

After save, the old value of the checkbox is what reappears, so if it was unchecked before, then you checked it and saved, on page reload, it will appear unchecked. Conversely, if it was checked before, and you unchecked it, then after save it appears checked.

The errant checkbox state doesn't appear to update, even after hitting the browser refresh button. However, if you navigate away from the E-mails tab entirely, then navigate back, the correct state (checked/unchecked) shows up. This implies that the value is being saved correctly, but through some other mechanism is not being displayed correctly.

Uploaded images demonstrate the issue.