This is a known lemmy bug (not unique to your app), when you delete a comment it puts the comment counter down by 1 every time you hit the delete button, instead of just 1 overall.

This means I can delete the same comment and, before it refreshes, delete it several more times and trick the instance into thinking I've deleted more comments than exist.

ironically this post shows -7 for me, and when i came to the comments there were a bunch of removed by user and only one actual comment

When the comments are toxic af:

Weird

Test

Negative comments aren't possible.