Fire TV-2 | Some PVR Channels are now “tiny”

Hi folks,

I have an M3U8 list, all channels were in full screen but now are in other small scale,for example:
I was watching CNN in full screen (as usual) then changed to other channel then back to CNN and now CNN are in other small scale, this is happening with others channels but not to all.
I can see all channels in full screen (as usual) in other application in the same TV and same TV-Fire.
I had tried change almost all the options but with not luck.

Any advice?

Thanks.