Steps to reproduce:
imported and configured as directed the: MySQL by Zabbix agent on Zabbix 6.0 for zabbix-agent (not zabbix-agent2)
I received a whole lot of: WARNING: Forcing protocol to TCP due to option specification. Please explicitly state intended
A whole log of statistics.
I had to modify template_db_mysql.conf. After making the change detailed below everything worked. Please note the addition of the parameter --protocol=socket to most of the configuration parameters.