Hi Nikolay,
Please go to Display settings (mouse right click -> Display Settings) and under 'Scale and layout' can you make sure that the scaling is 100%.
If scaling is not 100% please change it to 100% and try to run the test again.
If scaling is already 100% or you changed it to 100% but the problem still occurs, please go to 'Reports' tab, in your specific test details and under 'status' there is an error icon, click on it and take a screenshot of the error message and send it.