When moving an attachment, removing the extension and saving wrongly indicates that an attachment with the same name exists

Reproduction steps:

• upload an attachment ("picture.png")
• use the move action on the attachment
• remove the extension ("picture")
• press save

Expected result:
The attachment is renamed to "picture"

Actual result:

An error message is displayed:

Error: An attachment with the given name (demo_paragraph_numbering) already exists on Main.WebHome. Please provide a different name.