Graph API not returning SharePoint List items columns

I am using Graph API to get the content of a SharePoint Contacts list. I am using this uri:"https://graph.microsoft.com/v1.0/sites/$($siteid)/lists/$($listid)/items"

I am then using the id of each item to get the content with this uri:"https://graph.microsoft.com/v1.0/sites/$($siteid)/lists/$($listid)/items/$($id)"

It is returning the content but if a column is empty on an item it doesn't return that column so each item doesn't return the same number of fields. I would like to return all columns for each item in the list even if they are empty/null. Is there a way to change the uri so all columns are return even if they are empty?

I've tried expand=fields and select the columns I want but it still doesn't return empty columns.

$uri = "https://graph.microsoft.com/v1.0/sites/$($siteid)/lists/$($listid)/items?$expand=fields

$uri = "https://graph.microsoft.com/v1.0/sites/$($siteid)/lists/$($listid)/items?expand=fields($select=Title,FullName,WorkPhone,CellPhone)"