Did you install the MMM-ModuleScheduler after git cloning it? Do you see any error messages in the log of magic mirror
if run with pm2: type pm2 logs mm in terminal
if run manually: look at the terminal for any error messages
in browser hit F12 and look for console -> errors
@Brandlin
You might want to consider Jessie as opposed to Stretch. I had troubles with Stretch myself.
i have a pi zero kicking around, i might try it on there too see if i can replicate
The install on a Pi zero is different. There’s a bunch of threads relating to that.