Issue with a custom object form

Hello experts,

We're facing an issue when creating a form that holds custom objects created by Application Composer. We followed Shay's blog for reference but we still face the same issue.
When creating the form in application extension with the fields from the custom object, we get an error 'Save failedCould not create new Performance_c: status 404'.

None of our fields in the custom objects are required except for the RecordName, and this is our action chain of the Save button.

The fields are created normally in the application composer page with no errors as below,

Can anyone pinpoint the issue? is it an issue in the AppUI, the action chain or the object itself? We'd appreciate any form of help.