First off, thank you for this feature! Loved it back on Relay for reddit.
To reproduce the bug:
Start a reply on comment A
Back out of it
Start a reply on comment B
Your previously saved reply on comment A shows up on comment B
It's not consistent, but the restored comment shows up if you decide to create a second comment at the root level of the comment threat. (So basically not under any other comment, but commenting under the post directly)