Editing a field of a content type causes the display name to change directly to the technical name.

[chinasqzl]

V1.8.0

[giannik]

can confirm this happens

[giannik]

seems it is caused from this pr :
#14571

@MikeAlhayek maybe a check should be done if displayname is null before explicitly setting the displayname to fieldname ?

also here :
https://github.com/OrchardCMS/OrchardCore/blob/8f0c371e95bea724534280f2ee81801699ab14d2/src/OrchardCore.Modules/OrchardCore.ContentTypes/Services/ContentDefinitionService.cs

maybe use the async version :partBuilder.WithFieldAsync

 public async Task AlterFieldAsync(EditPartViewModel partViewModel, EditFieldViewModel fieldViewModel)
        {
            await _contentDefinitionManager.AlterPartDefinitionAsync(partViewModel.Name, async   partBuilder =>
            {
              await Task.FromResult(partBuilder.WithFieldAsync(fieldViewModel.Name, fieldBuilder =>
               {
                   fieldBuilder.WithDisplayName(fieldViewModel.DisplayName);
                   fieldBuilder.WithEditor(fieldViewModel.Editor);
                   fieldBuilder.WithDisplayMode(fieldViewModel.DisplayMode);
                   return Task.CompletedTask;
               }));
            });
        }