I have my "home" address set to a nearby corner (as recommended by security types) but sentry still stays off when parked in my garage. In fact, I'm pretty sure the sentry "home" has nothing to do with the navigation "home" since you don't have to enter a navigation "home" if you don't want to. According to the latest OM (have to look at some older copies I saved), sentry and navigation "home" are the same and it uses 32 feet as the boundary. I'm definitely more than 32 feet from my navigation home when I park but I wonder if it conflates the gps based scheduled charging location.
If you park in slightly different street spots from time to time, that might be a factor but, if not, maybe redoing the sentry settings could help. I'll definitely take a look at how mine is set when I get home.