Hi,
I have tried to reproduce your issue but failed.
Here are some of my attempts:
- Click on the link in an email with contacts of the same name but different email addresses.
- Modify mailboxes for contacts with hard bounced issues.
- Click operation with forwarding email.
…
Then I looked up some instructions for Hard Bounced Email. Some of them mention the following reasons except an invalid email address:
The email address of the sender has been blocked, the email itself is Rejected by spam filters or the mailbox is full.
These emails can be received into the Junk instead of the inbox. If they are opened and the links are clicked by the contact, there will be a record in the Email interactions.
However, it cannot reproduce with the common Email providers such as outlook or Gmail according to my test.
So, it’s necessary to figure out whether the contact's email is really invalid and whether the contact actually received your emails.
Also, if a link in the email has been clicked, there must be an open operation before this.

The top half of the timeline in the image you provided is obscured and it is not possible to determine what was done previously. If it is convenient, please provide the full timeline to pinpoint the problem.
If this helped you, I'd appreciate it if you'd mark this as a Verified Answer, which may in turn help others as well.
Best Regards,
Nya