When running 2 plans in parallel, Bamboo waits for both to finish before a new one can start

I created a new project, DEBUG, which has four plans in it: MASTER, SLAVE1, SLAVE2, and SLAVE3. All three slaves are dependencies of MASTER. Each of the four plans has a single job which runs the script, timeloop.rb. Each of those jobs requires an agent with "Debugger=1". There are only two agents (local) with that capability.

Timeloop.rb takes a single command line argument. The script loops for the number of times specified by that argument. The loop sleeps for 1 second then prints a message. At the end of the script, it prints a line indicating that the script has finished. In MASTER, timeloop.rb is set to run for 5 seconds. SLAVE1, SLAVE2, and SLAVE3 are set for 30, 60, and 90 respectively.

If when MASTER is run, it runs 5 seconds, then ends and queues all three slaves. SLAVE1 and 2 run immediately, SLAVE3 remains queued. When the script in SLAVE1 ends, Bamboo waits for SLAVE2 to end before starting SLAVE3.

timeloop.rb

$stdout.sync = true

time = ARGV[0].to_i

for i in 0..time
	sleep 1
	puts "Sleeping " + i.to_s + "\n";
end

puts "timeloop.rb finished\n"