Display Macro duplicates the content

If the display macro is used with a space in front, and one edits the page in the WYSIWYG editor (no matter if in-place or edit-mode, real-time collaboration on or off), then on save the contents of the page that got referenced is included below the display macro
Example

   {{display reference="Sandbox.TestPage1"/}}

Video of the bug:
https://private-user-images.githubusercontent.com/92780090/547878005-7bead2d3-b555-4f61-90d1-181871181692.mp4?jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.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.04553Q8hLYMWgP-4FjdxiAikMK4sUKOY12KFj_XbGI8