By default, the Contact owner and Company owner properties are independent and do not sync. This means a user who owns a company record may not own the associated contact records. If you want to keep the owners consistent between company and contact, turn on your sync ownership settings.
To sync ownership between contacts and companies:
In the left sidebar menu, navigate to Objects > Contacts.
In the Automation section, select the checkbox to Assign company owner to contact by default.
With this setting enabled:
This setting does not update the owner or records retroactively and it does not affect any custom HubSpot user field type properties.