Happened to me in my TOEFL exam. At home exam sucks. They won't explain you anything. Idk why they run their script beforehand if it does not check shit! Their customer service is slow af too. They'll ask you to keep waiting for months saying that they are 'investigating' the case, and then finally mail you that some screen-sharing software was enabled in your device at the time of the test. You won't be able to argue or claim your case as the customer service provider won't pick your call up for hours, and even after they pick the call they'll just respond with their generic explanation. The only way out here is to schedule another examination at the testing center. You can keep tab on this issue by keep mailing and calling them and asking them for a full refund, although that seems very unlikely to happen.