Tuplet notation bug

In a 2/4 bar I’m trying to create a septuplet of 16th notes on a quarter note beat. The way it should work is that everything up to 7 16th notes should fit and don’t become 32cd notes until it reaches 8 32cd notes per quarter note. It wants me to make the septuplet a 32cd note one which is wrong.
Is there a workaround?

You appear to have created a tuplet with the wrong base, so it has split across the barline.
The entry you need is 7:4x (7 semis in the space of 4 semis).

Good catch, @Janus, thanks.