Steps to reproduce:

1. Make sure you have Boost set up with at least two different accounts (e.g. abc@lemmy.world and xyz@lemmy.ml).
2. Make a note of which account you’re currently using in the main sidebar/drawer on the left (e.g. abc).
3. Visit a post and start making a comment.
4. Change your account to another one using the drop-down (e.g. change from abc to xyz)
5. Post your comment.

The comment will appear under the first account’s name (abc), instead of what you set in the dropdown.