Restricting Managers from Modifying the Attributes in the Web Portal

Just some options:
1: In the Admin portal: Configuration > Select 'Web portal'
Search for:
VI_Employee_MasterData_OrganizationalAttributes
VI_Employee_MasterData_Attributes
VI_Employee_MasterData_LocalityAttributes

And remove all the OOTB selected properties for each configkey
P.s. this is not exclusive to managers but for everybody with edit rights.

2: Table scripts (overwrite default permissions with.CanEdit)
If you want a more fine-grained option...
Use table scripts: Script (Onloaded) of the person table.

If AppData.Instance.AppType = AppType.Web AndAlso _
(Session.Principal.Groups.GetGroupNames()).Contains("VI_4_ALLMANAGER") Then
...
Entity.Columns("BirthDate").CanEdit = False
...
End If

3: Create a copy of the permisison group: VI_4_ALLMANAGER > CCC_4_ALLMANAGER
And modify the OOTB permissions to your company likings.
This is IMHO the most secure (on the lowest level), flexible and easy to manage

4: Customize the HTML application...
Overwrite the canedit option when person is manager look for in HTML application code:
this.isManagerForPersons = await qerPermissionService.isPersonManager()
canEdit: this.isPersonAdmin || this.isManagerForPersons,

HTH

Just some options:
1: In the Admin portal: Configuration > Select 'Web portal'
Search for:
VI_Employee_MasterData_OrganizationalAttributes
VI_Employee_MasterData_Attributes
VI_Employee_MasterData_LocalityAttributes

And remove all the OOTB selected properties for each configkey
P.s. this is not exclusive to managers but for everybody with edit rights.

2: Table scripts (overwrite default permissions with.CanEdit)
If you want a more fine-grained option...
Use table scripts: Script (Onloaded) of the person table.

If AppData.Instance.AppType = AppType.Web AndAlso _
(Session.Principal.Groups.GetGroupNames()).Contains("VI_4_ALLMANAGER") Then
...
Entity.Columns("BirthDate").CanEdit = False
...
End If

3: Create a copy of the permisison group: VI_4_ALLMANAGER > CCC_4_ALLMANAGER
And modify the OOTB permissions to your company likings.
This is IMHO the most secure (on the lowest level), flexible and easy to manage

4: Customize the HTML application...
Overwrite the canedit option when person is manager look for in HTML application code:
this.isManagerForPersons = await qerPermissionService.isPersonManager()
canEdit: this.isPersonAdmin || this.isManagerForPersons,

HTH