OK, I dealt with my problem.
If kodi started from Gnome Ubuntu session then no "PRIME Render Method" option available.
So kodi must be started as standalone session, then non-standard dimension video is displayed properly.
Also if kodi-standalone started from ssh, then video is played properly. But if kodi-standalone started from terminal in Gnome session then again the same problem (and no "PRIME Render Method" option).