I see that you completed that test now (and got a good score – well done!). Are you still having problems?
It’s hard to say what happened. Perhaps the page got refreshed somehow by accident? The system saves progress every minute. If you hadn’t finished that section the system would have taken you back to the first question of that section when you resumed it.
I can see that you’ve been completing tests since then so hopefully everything is ok now.
Let us know if you need further help.