Steps to reproduce:

OS: Centos8

1. Install mysql8-0-21
2. Install zabbix-agent2
3. Configure it and launch
4. Collect item 
   mysql.db.size["\{$MYSQL.DSN}","\{$MYSQL.USER}","\{$MYSQL.PASSWORD}","mysql"]

Result:
MySQL segfault, see log1.txt

For MySQL stacktrace see log2.txt
Expected:
Value