Cambridge Latin Course glitch?

The course will not accept ‘?’ as the answer to 3DSN. (See image). In review it will accept ‘?’ but there iOS no mechanism to press ‘next’. The only way to proceed is to eliminate the ‘?’ and recording an error. Very frustrating. I am using a Mac. Anyone else have the same annoying prob?

I’ve never seen this problem. I’d suggest you simply “ignore” this word.