Getting a -99 parameter when running a scan

I recently installed the OpenVAS vulnerability scanner in my environment. I tried to conduct a scan and after the scan was completed, I manually tried fetching the report, but the report was empty and the severity was “-99.0”. (Point to be noted is OpenVAS will share severity as ‘-99’ if the host is not alive), but In my case the host is alive. Can someone provide a solution as to why I’m getting this -99 for the severity. Thanks.