Second chime alert when opening Messages on iPhone 16 Pro

Hello, hoping someone can help with what I believe is a settings issue for Messages notifications. I currently have "Allow Notifications" as on, and to receive a chime alert as well as within Banners. When I receive an incoming text everything works as it should. However, I also receive a second chime alert when I actually go to open the message.

So for example, I'm driving, receive an incoming text message, and the iPhone makes a chime sound. Later (could be a minute later or hours later) I go to open/read the message and receive a second chime sound.

The second chime sound is both unnecessary and annoying. I've gone through the Notifications settings but can't find anything that points to why it'd be doing this.

I have an iPhone 16 Pro and updated to iOS 18.6.2 a couple days ago (although this has been going on for weeks/months).

Thank you in advance for any thoughts you may have on this. I expect this is likely a new "feature" that Apple rolled out and that there's just a setting that this dummy can't figure out!

[Re-Titled by Moderator]

Original Title: Messages notification setting