Bug? Form node hidden values are missing or incorrect

[SKis]

Describe the problem/error/question

Hey there. I’m using the form node with hidden field element types. When submitting the form some fields are undefined instead of the field name and some values are complety missing (2x hidden but just 1 undefined).

What is the error message (if any)?

There is no error message but the output is incorrect.

Please share your workflow

Share the output returned by the last node

[
  {
    "MAC-Adresse": "jidsajdhafa",
    "undefined": "Nicht relevant",
    "submittedAt": "2025-03-19T15:39:56.827-04:00",
    "formMode": "test"
  }
]

Information on your n8n setup

• **n8n version:**1.84.0
• Database (default: SQLite): PostgresDB
• n8n EXECUTIONS_PROCESS setting (default: own, main): default
• Running n8n via (Docker, npm, n8n cloud, desktop app): Docker
• Operating system: Ubuntu 24.04

[jcuypers]

Yes, so you are right. I quickly tested it. all hidden fields show up as undefined and only the last value is recorded if you put multiple only the last value is visible. on the form page itself the field names are just generic. field1, 2 , 3