"Allow notifications from iPhone" won't enable or stay enabled

I have an iPhone 15 pro with iOS 18.1 and Mac Mini M4 with MacOS 15.1.1. I've used iPhone Mirroring to connect my phone to the Mac. When asked, I allow notifications but notifications from the iPhone isn't working. When I go to Settings -> Notifications on the Mac, "Allow notifications from iPhone" is not visible. But if I search "iPhone" in Settings, "Notifications from iPhone" appears in the results. I click on it and the toggle for "Allow notifications from iPhone" is off. If I enable it, I see all my iPhone apps listed. If I click back to Notifications, "Allow notifications from iPhone" is visible. But, if I close Settings and reopen it, "Allow notifications from iPhone" under Notifications is again missing. Going through the search process, it's disabled.

I've tried revoking access to the iPhone and restarting both iPhone and the Mac and then going through iPhone Mirroring again but it doesn't fix the issue.

Does anyone have any suggestions on how to resolve this?