Problem with limiting concurrent game session activation on new instance

I set up a very bare bones test game and server in Unity to try GameLift. On a c4.large a server uses between 0% and 1% of the CPU, but while it is launching it uses 5% to 7%, so I set the max concurrent game session activation to 1 just to be safe while testing.

If I create a fleet and set concurrent processes to 10 (server auto finds an open port), then once the fleet is activated, I change the concurrent processes to 50, it works fine.

If I instead create a fleet with 50 concurrent processes, once the fleet says active and I check the available game sessions on the metrics tab, and it will say somewhere between 30-45 sessions are available. The events tab will show “Server process exceeded 3 minutes without reporting healthy” several times, then a minute or two later, there will be 50 available game sessions on the metrics tab.

My best guess is that max concurrent game session activation does not apply until the fleet is active, and when its trying to launch 50 processes at the same time, it is going so slow that not all of them can report healthy in time.

Any help would be appreciated.