What user permission type is lacking if a user cannot edit their status on a project sheet because it has become read-only?

The user permission type that is lacking in this scenario is Editor. When a project sheet is set to read-only, users are restricted from making any edits, including changing their status. An Editor permission allows users to edit rows within a sheet, which includes modifying statuses. If a user only has Viewer permissions, they can see the information but cannot make any changes.

In this context, to enable users to edit their statuses or any aspect of the project sheet, they must have at least Editor permissions. Owners and Admins have full control over the sheet, including the ability to make edits and manage permissions, but if a user cannot edit their status, it's likely because they do not have Editor rights.