Resolved
Reported for: Toolset Forms 2.0
Resolved in: Toolset Forms 2.5.7
When you auto-generate a Toolset Form or manually insert a cred-form-submit shortcode to any Relationship Form, the label attribute cannot be edited using the user interface and is not added when inserting the shortcode either.
Fixed
[cred-form-submit]submit[/cred-form-submit] This is the workaround 😛