Notification Error after submission

Describe the issue or problem
After every submission, the notification automatically starts showing “An unexpected error has occurred. Please reload the page and try again.”

Steps I took leading up to the issue
I checked the error log and found this message “[19-Oct-2025 21:12:12 America/New_York] PHP Fatal error: Uncaught UnhandledMatchError: Unhandled match case ‘16777247’ in /home/kaduylnz/public_html/lib/pkp/classes/notification/managerDelegate/SubmissionNotificationManager.php:42“

What application are you using?
OJS 3.5.0-1

Additional information
Once I truncate the notification table via phpmyadmin, the notification starts working again. But once there is a new submission, it continue showing “An unexpected error has occurred. Please reload the page and try again.”

Could you please let me know what version of PHP you are using? Did you host OJS on cPanel or VPS?

The version is 3.5.0.1, installed via Softaculous. We are using shared hosting provided by Namecheap.

Hello, please any idea how to fix the issue above?