Form inputs do not display associated list of errors

What you were expecting:

I would see two error texts below the input concerned by the error

What happened instead:

The input is actually red, showing there is an error, but not displaying the text provided by the API

Steps to reproduce:

• Go to this sandbox: https://codesandbox.io/s/broken-voice-dd8zth
• On the Tag page, try creating a tag (with french and english labels). Save.
• You should see the french error displaying correctly on the field while the english errors are not displaying

Related code:

Sanbox https://codesandbox.io/s/broken-voice-dd8zth?file=/src/dataProvider.tsx
I created a custom useSubmit hook whose purpose is to display errors associated to the fields concerned by the error

Other information:

From my investigation, the bug comes from the way setSubmissionErrors sets the error.
I'll try creating a merge request and adding a test to handle lists of errors associated to a field

Environment

• React-admin version: 4.4.3
• Last version that did not exhibit the issue (if applicable): N/A
• React version: 17
• Browser: Google Chrome: Version 106.0.5249.119 (Build officiel) (x86_64)
• Stack trace (in case of a JS error): N/A

Reproduce the issue in the linked CodeSandbox, starting with src/dataProvider.tsx and the custom useSubmit hook. Then inspect packages/ra-core/src/form/setSubmissionErrors.ts and add the regression test mentioned in the issue. Done means multiple API errors for one field are displayed, including the French and English errors.