Repetition of character

[emanuelgsouza]

Describe the bug
Some of generated questions is about a character that have already previous selected.

To Reproduce

Expected behavior
The characters cannot repeat

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

Smartphone (please complete the following information):

Additional context
When create a new question, is it possible to ignore the previous characters?

Thanks for @fernandohenriques by report the issue