Hi,

Odoo read company details from the Document Layout configuration, so you can go to Settings -> then under Companies section click on  Configure Document Layout

Then remove any empty lines in the "Company Details":

If this not the issue, then there is another cause for the issue, if you entered "Company Tagline" in the document layout then you removed it, the field will not be empty because it HTML field and it will have break line tag so to solve this issue, you need to open companies list view and then export the following company fields to excel (id, report_header) and then remove the HTML code from report_header column and then import it again.