Loosing TV signal in fullscreen mode?

#1
When working in windowed mode with screen size ~800x500 everything is normal. When swich to fullscreen mode or stretch window on whole screen, image starts to fall into greenish squares and video freeses like as there is bad antenna signal. After returning to small window everything becomes normal.
I try to use different video settings but it does not help.

It is happens only whith TV channels, internet ones works good.

Is it problem with program or tuner?

Program version: 2.15.09 Standart edition x64
TV-tuner: Rombica Pro DVB-T2