There’s already a (.
There’s already an ✕ but LanguageTool detects a mistake anyway.
I checked about this specific sign and there are 2 really similar,
× is a
Multiplication Sign while✕ is a
Multiplication X, this is what my system fonts software says when I click them. By the way, this isn’t important as it’s a screenshot, LanguageTool always detects the sign there but it’s a default title for attachments so 
.
This
for even more.
And if you wanted that funny GIF, here it is
.