The last several days it doesn't seem to be working for me anymore. Sometimes it shows the icon, but generally it is not showing the messages.

Yeah, I'm having the same issue. Prior to the update it was working fine for me but now it's not working either

Yep, Christmas update borked this plugin. 

I found the issue. It wasnt a facepunch update that broke the plugin. Looks like the config changed. Save your current config to a different location. Then, delete your config. Reload the plugin. You will notice the config doesnt have some lines that the old one used to have. Copy and paste the info you want from your old config into the new one.

Yea, I thought I noticed all my messages were missing from the config. I moved to another loading screen plugin and when I went to copy them they were gone. How do you know that Facepunch is to blame though? Do Facepunch updates typically wipe plugin config files? Especially only 1 out of 160+?

Check the changelog, it shows there's a new config and the option being removed.