I'd say that the issue is that you're trying to kick as well, which is probably stopping you from pushing down on the tail.
Keeping your legs straight and together should improve things.
Although it probably also doesn't help that it appears to be a rather tricky wave, because it seems to have a peak on your right, which you're going for, but then it actually suddenly draws up and breaks on your left, leaving you on the shoulder ☹️
Commented on Good day all, I’ve been practicing th...
09 Oct 20:10
When you're coming up, you end up with your hips high and your knees pointing in different directions.
Try lying on the floor, look at the wall in front of you, then just stand up and walk towards it.
You should find that your knees automatically point forwards, so practice that while thinking about doing it on your board.
(And the Lifeguards really should have a word with the idiots paddling across the shoulder!)