Can you be more specific? You should spawn with more than what's maximum and it will take some time before it drains into visible stage IIRC.

I played for a good twenty minutes and the bar literally didn't drain at all.

@Dune-Jumper Did you make any changes to your config file? If so, please post your config file to http://pastebin.com and paste the link here so we can read it.

That's odd, I just tried it again and now it's working. Maybe I had an incompatible mod and unknowingly got rid of it?

Is there a way to adjust the drain rate in the 1.10.2 version? Now that it's working it's draining a bit too fast imo and I don't see a config for it. I remember there was a config for it in 1.7.10. In fact a lot of options seem to be missing now, such as being able to disable ground sleeping.

You can adjust config's all the tirednessmodule configs to set that.