Google Home and Assistant

I have setup SimpliSafe with Google Home and Assistant.  Used to work fine.  I have it setup to arm the system to Home mode at a certain time after dinner, in case we forget to arm it.  I also then have it switch to away mode after we go to bed, in case we forget that (so it changes from Home to Away).   I thought it worked fine, but recently noticed that it doesn't.

I know I cannot disarm the system with Assistant, but am I prevented from switching from Home to Away modes also?  And did this recently change?