- Official Post
I've checked the issue and this is an issue caused by the way Grammarly works. Instead of overlaying the page at a specific position, it injects custom elements into the DOM, right next to the text input field.
Unfortunately this causes the JavaScript to fail as the the text input and submit button are no longer adjacent buttons, because Grammarly injects an element between them. I will see what I can do to work around this.
Oh, and just for clarification: Grammarly is at fault without doubt and it even causes CSS rules to no longer properly apply because of the arbitrary elements being inserted. You can even observe it by toggling the enabled state of Grammarly for the page, as the textarea flashes white for a moment due to the changed DOM order.