Slow test execution with latest server bits

Hello Folks,
I redeployed my server private instance with the latest bits from Github in order to get Lighthouse functionality. Lighthouse worked great but I had to roll back since I discovered that test execution times were greatly increased and my agent farms were not able to keep up. I logged on to an agent to watch a test execute and saw that the test successfully ran to completion and the browser window closed, but wptdriver was still saying “waiting up to 120 seconds for test completion”. This was not the behavior before deploying this version and since rolling back its working fine again. Agent configuration was unchanged, only the server was updated. Has anyone else seen this type of behavior? I’m blocked from getting Lighthouse data because of it.