Why code first approach migration is adding records where it should update

Issue: Below code has added the 6 records properly. But when I try to update the Name field in object with the 'Hospitality' then migration is adding the record instead of updating the record.

Code snippet:

ProjectType toolRetail = new ProjectType() { Id = SequentialGuid.NewGuid(), Name = "Retail", Path = @"App_Data\RetailTool.xlsx", CreatedOn = DateTime.Now, NoOfTabs = 3, DisplayOrder = 3 };
ProjectType toolOffice = new ProjectType() { Id = SequentialGuid.NewGuid(), Name = "Offices", Path = @"App_Data\OfficeTool.xlsx", CreatedOn = DateTime.Now, NoOfTabs = 3, DisplayOrder = 4 };
ProjectType toolHospital = new ProjectType() { Id = SequentialGuid.NewGuid(), Name = "Hospitals", Path = @"App_Data\HospitalTool.xlsx", CreatedOn = DateTime.Now, NoOfTabs = 3, DisplayOrder = 5 };
ProjectType toolEducation = new ProjectType() { Id = SequentialGuid.NewGuid(), Name = "Education", Path = @"App_Data\EducationTool.xlsx", CreatedOn = DateTime.Now, NoOfTabs = 3, DisplayOrder = 6 };

_ctx.ProjectType.AddOrUpdate(c => new { c.Name }, toolHome);
_ctx.ProjectType.AddOrUpdate(c => new { c.Name }, toolHotel);
_ctx.ProjectType.AddOrUpdate(c => new { c.Name }, toolRetail);
_ctx.ProjectType.AddOrUpdate(c => new { c.Name }, toolOffice);
_ctx.ProjectType.AddOrUpdate(c => new { c.Name }, toolHospital);
_ctx.ProjectType.AddOrUpdate(c => new { c.Name }, toolEducation);

_ctx.SaveChanges();

Let me know where I need to change the code to fix the issue.