Thank you for your question.
You can stop the Visibility from appearing by the following two ways.
1-1. Open the context menu of the class on the diagram
1-2. Select [Extended Visibility] - [Visibility Kind Visibility]
2-1. Open [Initial Visibility] tab of the property view for the class diagram
2-2. Check off [Attribute and Operation Visibility Kind Visibility]
2-3. Click [Apply to existing elements]
If you have further questions or requests, please let us know at any time.