Fatal error 1408 when installing mariadb-server / mariadb-upgrade

I recently upgraded a Debian 10 server running MySQL 5.7 to MariaDB 10.3. That upgrade went smoothly so I then upgraded to Debian 11 and MariaDB 10.5. That also went smoothly. I then upgraded to Debian 12 and MariaDB 10.11. While performing that upgrade, I encountered an issue with mariadb-server:

Setting up mariadb-server (1:10.11.4-1~deb12u1) ...

dpkg: error processing package mariadb-server (--configure):

 installed mariadb-server package post-installation script subprocess returned error exit status 1

Processing triggers for man-db (2.11.2-2) ...

Processing triggers for libc-bin (2.36-9+deb12u3) ...

Errors were encountered while processing:

 mariadb-server

E: Sub-process /usr/bin/dpkg returned an error code (1)

I recently upgraded my Debian 10 server running MySQL 5.7 to Debian 11 and MariaDB 10.3. That upgrade went smoothly. I then decided to upgrade to Debian 12 and MariaDB 10.11. While performing that upgrade, I encountered an issue with mariadb-server:

Setting up mariadb-server (1:10.11.4-1~deb12u1) ...

dpkg: error processing package mariadb-server (--configure):

 installed mariadb-server package post-installation script subprocess returned error exit status 1

Processing triggers for man-db (2.11.2-2) ...

Processing triggers for libc-bin (2.36-9+deb12u3) ...

Errors were encountered while processing:

 mariadb-server

E: Sub-process /usr/bin/dpkg returned an error code (1)

I re-ran apt install mariadb-server and got the same error. I then ran apt install -f and dpkg --configure -a but they both returned the same error as well.

Next, I ran apt purge mariadb-server and then tried to reinstall with apt install mariadb-server and got the same error as above.

It appears that the installation itself succeedes as I was able to run systemctl start mariadb so that I could then run mariadb-upgrade but that failed part of the way through with:

Phase 4/7: Running 'mysql_fix_privilege_tables'

ERROR 1408 (HY000) at line 429: Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler.

FATAL ERROR: Upgrade failed

/var/log/mysql/error.log shows a few errors related to a column type mismatch for mysql.event table but I'm not sure if that is related to the mariadb-upgrade/mysql_fix_privilege_tables error or not.

I ran mariadb-check --check-upgrade --all-databases and all of the tables were marked as "OK".

Running SELECT @@Version; returns "10.11.4-MariaDB-1~deb12u1" so the upgrade appears to have been mostly successful but I'm not sure how to fix the privilege tables.

In addition, every time I run apt install or apt upgrade, dpkg attempts to configure mariadb-server, which kills the mariadb.service. So, I need to figure out how to get this issue resolved.