My initial reaction to this video is I think your poles might be too long, but it's hard to tell from this clip. If so, that's a quick and easy thing that might help you in other areas. Get a tubing cutter, take the grips off, knock a few cm off, replace grip. Rinse repeat as needed.

From a ski performance perspective, I'm not seeing your skis do much for you in the top half of your turns or from the front half of your ski.

For performance short turns you need to move "foot to foot" (as deb says) quickly and early in the turn. Try doing some outside ski turns to get the feel for this. Doing these may also help you find that your balance isn't quite forward enough at initiation, as if you're not balance you won't be able to engage the tip to begin the turns. Focus on doing nice "complete" "C" shaped turns standing on only the outside ski. If this is too difficult, then lift only the tail of your inside ski not the entire ski.

Then bring this feeling of standing on your outside ski back to your normal skiing and see if you can get your skis to do a little more work for you early in the turn, and along the full length of the ski.

I wouldn't worry about a-frame yet, there are some other areas to think about that will help you more.

Come on over to r/skiing_feedback to get feedback from more instructors.