Not working at the beginning

before interview started I tested everything was fine but just after interviewer started just first question Parakeetai not listening to interviewer basically nothing on my screen even same question asked twice and thrice. this is not the first time happened, it happening twice to me, Application is not dependable, I can’t trust anymore I lost my credits due to I have closed and activated three times and also interview gone due to not able to answer properly.. Fix the bug, I have latest application in Mac and I updated and tested 100 times before interview but not sure why this is happening during interview..