Problems

I have problem with the test results. When I finish a test I click on the “check” button. Then when the results turn up on the screen it turns out that my answers were changed by the system. For instance: I ticked answere “A”, which was correct answere, but the system changed it on answere “C”, which was wrong naturally.
Finally instead of 10/10 I’ve got 5/10.
Can anybody explaine me this?

Which test?

Any test. Doesn’t matter which test I do I heve been experiencing the same problem. The system is changing my answeres. Not all of them, some of them.

Please provide a specific example of a test where the system changes your answers. It would help if you could also indicate which answers you are trying to give.