iOS app becomes unresponsive frequently

iOS app becomes unresponsive. Pressing buttons doesn't work. It does not work even if I press 5-10 times, and many times when it works, the output is completely different from what was said. A few times it just returned "." as the output.

Works perfectly fine on macOS, although switching the app for enabling mic(on ios) is an irritant but livable. But the app actually needs to be responsive for it to be a workable experience.