If you select anything on chat, the last symbol will have one line of pixels that didn't get selected. Except if you have a space at the end.

Steps to Reproduce:

• Paste the following characters into the chat but don't press enter.

  aaaaaaaaaaaaaaaaa
  

• Highlight the text by pressing (CTRL + A).
• → Notice how the shadow of the character on the far right is highlighted.
• Deselect the text.
• Highlight the text by pressing (CTRL + SHIFT + LEFT ARROW).
• → Notice how the shadow of the character on the far right is not highlighted.