Issues with no sound for notifications on my iPhone 16 ProMax running iOS 18.6.2

I am having an issue with sound on my iPhone. I am not getting any sound alerts for texts and from other apps I have notification sounds turned on for (for example, Slack, Amazon, Konstella, Signal, Vivint). I am getting sound when someone calls me or FaceTimes me, and when I play a video from Photos I get sound.

I have confirmed that I don't have a Focus on and Do Not Disturb is not on, I have checked the settings in Notifications for each app that I am not getting sound notifications for (they all show "Sounds" as turned on in Notifications), I have restarted my phone, I have ensured all of the apps and the iOS is up to date.

Any advice? What else can I try? Thanks in advance!