Help with a Elitebook 840 G4 after following the guide

I followed this guide with my Elitebook 840 G4 and it works... mostly...

Everything is fine until some random amount of time later at which the mouse cursor starts (what seems like) lagging with overall system slowdown...

Once this starts, going into sleep, shutting down, or restarting causes the system to restart at which point it displays a kernel panic message

The specs are:

Elitebook 840 G4

i7-7600U

512GB Intel NVME SSD

WWAN card

16GB RAM

BCM94352Z wireless card