When a chain resolves during a showdown, does the showdown end immediately, or do players get another opportunity to play actions?

Ruling: After a chain resolves during a showdown, players get another opportunity to play actions. The showdown only ends when both players consecutively choose not to start a new chain.

Sequence:

• Showdown begins
• When I attack/defend triggers are added to the chain (if any) and resolve
• Attacker gets focus and can start a chain (play actions)
• Chain resolves completely
• Focus passes to defender, who can start a new chain
• Focus passes back to attacker if defender doesn't start a chain
• This continues until both players consecutively choose not to start a chain
• Only then does the showdown end

Nuances:

• Focus passing automatically after a chain resolves is not the same as a player passing focus
• Both players must consecutively NOT start a chain for the showdown to end