Failing process:
Install mariadb from ppa using apt (happens through salt, fwiw)
Download last night's backup from a 10.6.4 server, which is a replica from a galera cluster.
run the script attached restore_mariabackup.sh

Once this is done the database itself works, for our application, but any client trying to access anything that requires mysql.proc gets an error similar to:

Sep 30 19:29:07 devmaria /etc/mysql/debian-start[24656]: error    : Corrupt
Sep 30 19:29:07 devmaria /etc/mysql/debian-start[24656]: sys.x$schema_table_statistics
Sep 30 19:29:07 devmaria /etc/mysql/debian-start[24656]: Error    : Cannot load from mysql.proc. The table is probably corrupted

I just built two new servers, one that builds mariadb and then overwrites the data from a backup and one that just installs mariadb.  The two different files base_install.proc.sql and backupedup.proc.sql.  The error output from sudo mysql_upgrade on the server that received the backup is in mysql_upgrade.out  

There are more differences in the proc table if i dump the data as well, but i think much of it is driven by the utf8_mb4 rather than 3. 

Tried to keep this sucient and use attachments.  This process has worked for me for until i upgraded to 10.6.4.  Please ask anything you need. I think i've been using this similar process to build dev machines since about 10.4

Thanks
Jeff