This is supposed to happen as once this is added to an Application it should not be deleted.

Most if not all of the time, Schools will want to use Entering Year and Entering Grade so this block should always be included in an Application. If it is not included, you will not know for which year and grade a student is applying for which could also cause undesired results in the Software.

There is an Idea in the Ideas portal to hopefully be able to include this in a future request, to either allow the delete option, or require this block. You can vote for it by going to: https://blackbaudk12.ideas.aha.io/ideas/K12OB-I-813.