When adding a new Emergency Contact, there is a character limit of 30 characters in the Relationship field. The user has no idea of knowing this- there is no label saying there's a limit, and the system doesn't throw any errors or prevent the user in any way from entering more than 30 characters. It allows you to enter as many as you want and then you can't save and you can't delete your entry and you have no idea why. A super quick "fix" would be to just rename the field "Relationship (30 characters max)" or something along those lines.
On the new contact card, available as of April 2023 on the 360 profile only, the field will now highlight in red as the user types if the characters go above 30. This new contact card will be rolled out to all other profiles for consistency across the app.