Export Failed - unsupported type <class ‘list’> in write()

Hello, I have KoBo on my own server, using the source code from August 31st 2021, and I’m facing issues when exporting to XLS. In fact, I always get a failed export with this message:

unsupported type <class ‘list’> in write()

It does not matter which questions I have on the form. It even fails with a basic form with three questions (text, date and number types) and the default IDs the system creates.

In the meantime, I am using the “XLS (legacy)” option, which is working well.

Could you please advice on how to fix the export issue, or could you confirm that the latest release from September fixes it?