Hang during play "gpuEvent - firmware detected lockup"

Hey, so I'm testing my game on my iPhone 5s (iOS 10.3.3). During play the game will randomly pause from anywhere between 1-3 seconds. I can't find out where this slow down is occuring. I started looking at the analytics logs on my device and noticed hundreds of "gpuEvent" logs. Opened them up and saw this

gpuEvent-myProject
bug_type: 284
restart_reason_desc: "firmware-detected-lockup".

I haven't been able to reproduce the slow down on an iPhone 6 - 7. Seems to jut be a 5-5s thing.

Any...

Hang during play "gpuEvent - firmware detected lockup"