Multiselect Field Error: FrappeTypeError - Expected str, Got list

Hi everyone,

I followed the documentation for the multiselect field: Table Multiselect Field. However, when I try to save the form, I get the following error:

frappe.exceptions.FrappeTypeError: Argument 'company' should be of type 'typing.Optional[str]' but got 'list' instead.

In my DocType, I am using the Company DocType as a multiselect field. It seems like Frappe is expecting a string but receiving a list instead.

Has anyone encountered this issue before? Do I need to convert the list to a comma-separated string before saving? If so, what would be the best approach to handle this?

Any guidance would be appreciated!