Beginners might not benefit much from doing a bodypart split. I know some will disagree with me on this, but hear me out.
You first need to learn your body. This will take maybe 2 more years. You need to develop both the strength and body awareness necessary to hammer one body part and have worked it sufficiently for one week.
Until then, keep frequency around twice a week. Consider following a 4-day upper/lower split as opposed to a bodypart split.
Finally, the basics of your split really doesn't tell us a lot about how your training your chest and your bench press. What you're doing on Chest Day could just suck. It's possible that you're actually build to bench press but your bench training sucks while you're doing some stuff right with your squat and deadlift.
You're not going to get better at Benching if you don't get better at moving a barbell through a horizontal plane. Chest Flys, Machines, and Triceps Pushdowns aren't that important. Pressing is what matters.
It's also no secret that strong triceps are what build a big bench press. Heavy Board Presses, Close-Grip Benching, and Floor Presses with a pause will build much stronger triceps than any sort of extension.
But if you just want a big chest and you're more interested in bodybuilding, then don't pay attention to your power lifts as much. Go by how you look. Use Incline Bench Press, Hammer Strength Machines, Chest Dips, Dumbbell Work, and other exercises that are heavy but allow you to feel the chest work. Gauge the effectiveness of exercises by pump, size, and stretch marks.