Your cam isn't in corridor mode, so no worries there (my Dahua in corridor mode misses triggers when I use multiple zones unless I uncheck object travels and object size exceeds--but then I get too many false alerts).
With filters I meant Object travels, Object size exceeds, etc.
You should know rather quickly if those setting changes made a difference. If you're consistently getting the alerts now, you can add back those settings one at a time to see which one (or more) was preventing triggers. Keep in mind, zone A is rather thin at the end of your driveway, so if an object enters that area first, you'll need to have your minimum object size rather small for BI to detect the motion...especially at night (at night you'll want the contrast to be lower too--you may have to setup a different profile for night time). Trigger boxes can get larger than the actual target when it moves (especially at night), so it might be wise to increase the 'Object size exceeds' to 50% or leave it at the default of 67% (at night, headlights will create a BIG trigger box, so you may want to leave this setting unchecked if you have a separate profile for night time).
I've made the mistake of misdrawing zones in the past...not sure how I did it, but I did. For instance, I drew zone A, zone B and zone G (my catch all to link zones A&B). During troubleshooting trigger problems, I've found on more than one occasion where I had a stray zone square not connected to anything...so check your zones carefully.
If by chance you're recording 24/7 on this camera, you can make changes to the trigger settings and re-run the video with 'test run video with motion detector' to see if BI registers the previously undetected motion as triggers.