Follow-Up: Waiting for approval is shown to "wrong" user

Hi, this is a follow up to an existing thread. I'm not quite sure if my last response has been recognized, therefore I opened this thread. Hope, that's okay. 🙂 

The issue still remains with version 7.6.20.

Summary:

• Users can leave comments with their name and e-mail without being registered.
• Not often but sometimes an unregistered commentator sees the "Waiting for approval" message on a comment which has been submitted by another unregistered commentator with another e-mail address (see screenshot).

Can it be a caching issue? Are there any additional information we can provide in order to solve the issue?