Time Machine broken on GBA Emulators

The Time Machine feature isn't working on John GBA Lite or My Boy! Free. However, it does work on Timely so I know that it can work on this rom/device/kernel.

Device: Nexus 5
Version: 4.4.2
Kernel: 3.4.79-franco.Kernel (i.e. Franco Kernel -r33)
Xposed Framework: 2.4.1
Per App Hacking Version: 1.5
John GBA Version: 2.21
My Boy! Version: 1.5.22

t2k269 / PerAppHacking

Time Machine broken on GBA Emulators #11