To be honest I have no idea what is needed by the kernel for the bios to beable to check that the os is responding correctly. I enabled it on a test server and had the same issue on a default 4.6 cent install. I could have the name in the bios (the service ) incorrect ie, watch guard,watch dog , watch "something" I know it is psent on serval types of motherboad manufactures. Take a look should be easy to find