the combine function documents doesn't combine the files, but repeats the 1st doc

Are this documents with form fields?

Hi Jarne29718341jege,

Sorry about the delay in response.

If the issue still occurs, try combining files on the Acrobat Online account and check if that works.

Open the link https://acrobat.adobe.com/link/home/ and sign in using your Adobe credentials. Go to the Edit tab and select the Combine files option in the list for Organize a PDF. Or refer to the steps suggested here: https://helpx.adobe.com/document-cloud/help/combine-files-pdf.html. 

Please let us know the steps you do to combine the PDF. Are you using Acrobat's combine files tool or the right-click option after selecting the files in Windows Explorer?

Share the Acrobat and OS versions on the machine. To check the application version, use the steps provided in this help document: https://helpx.adobe.com/acrobat/kb/identify-product-version.html. 

Let us know if you need any help.

Thanks,

Meenakshi