Coverage breakdowns

Am I doing something wrong or is everyone else’s defense periodically not running the play I called? For example I’ve been burnt deep on 3rd and long multiple times after calling cover 4 and both safeties doing anything but covering the deep zone where they are supposed to. Tampa 2 do we think the corner is covering the flat? Absolutely not he’s running with the guy running a slant as if I called man coverage. It’s especially annoying when I know the play I called would have defended the play they ran.