When we first start one ski skiing, one of the first things that happens is we start to "stiffen" the foot and try to tip BTE to LTE and back to BTE. sometimes rolling the foot, sometimes driving the knees, sometimes banking..
What often goes away is the flexion-extension of the ankle, and pressure on the front of the ski through the boot cuff/tongue.
Some video of you skiing (especially on the harder balance point), close up, not a POV camera, would be extremely helpful here are some hints.
Think about flexing and extending. Try just making some basic parallel turns with almost no weight in the outside ski (using just the inside ski to initiate each turn) Keep the focus on gentle steering, and flattening, then steering to an edge using flexion and extension of the ankles to edge/flatten the skis. Ski into and out of counter, using slight amounts of knee/hip angulation to stay balanced. (not balancing by tipping in further, then using the outside ski as a counter balance).
When these become very comfortable, then lift the outside ski but keep the tip of the ski on the ground. Use it as feedback for your balance. Again your focus should be ankle flexion/extension for edge release/engagement with a little bit of rolling of the foot BTE to LTE. this should result in the knee and hip moving inside the turn but the body staying more upright..
When this comes together, then you are ready to start lifting that ski all the way off the ground. Still focus on the ankle flexing and extending.. Once you no longer have any other contact with the ground other than the one ski, you will also find you need to have a much tighter core. (suck in those ab muscles) to make them more disciplined.
Another hint.. try to get the ski that's up in the air, to match the edge angles of the one on the ground. almost like you are skiing on it.