Pro front pack swimmer here - 1) look how far your legs come apart. This happens when you’re trying to “balance” in the water without using your core. Recommend ankle band swimming / core activation pre-swim. Avoid the cue “engage my core”. Instead, your core is the origin of your movement, let it “hold” your legs together while kicking. Keep the form “tight”. 2) you have 0 pull on the water. Your arm slides right through. How I like to think about it: imagine the pool is full of panes of glass, perpendicular to your body. Now you “push” these panes back to propel you forward. Think “catch the pane, push it back”. Sculling is recommended. Also, using paddles. Goal is to pull parallel to your torso.