How do I stop my souflee pancakes from deflating!

before and after I lifted the lid. they were fine when I flipped it, and I didn’t open the lid after flipping it until it was done cooking. recipe:

2 large eggs

30 ml (2 tbsp) whole milk

24 g (3 tbsp) all-purpose flour

1 g (1/4 tsp) baking powder

1/2 tsp vanilla extract (optional)

1/2 tsp lemon juice (optional)

26 g (2 tbsp) sugar

Japanese Pancakes Recipe Short

insgead of lemon juice I used cream of tartar and I cooked it on low for 5 then 8 minutes using water steam, canola oil lightly rubbed and a metal pan