HR21 Space free issue

I have a HR21/200 with software 0x40d downloaded on 8/25.  Our space free when from 42% to 4% free overnight. So I reset the machine using the red button that didn't work. Then I tried the checking for errors and that erased some programs but didn't change the free space issue.  I have whole-home service on the machine. Not sure what else would need to h elp with this prioblem.  Mahalo in advance for any advice or support.

Aloha