mixed monitors

wondering how to fix this issue:
In a multi monitor set up of both 4k and 1080p monitors. Videos HD movies & T V programs will only play on half of the screen while playing 1080p rips. However standard def i.e. 480i well play with no problems. If the 1080p monitors are turned off as not in extended mode, but not physically unplugged high def both 720 and 1080 rips will play with no issues. This happens in both kodi 16 and rc 17. thea

not sure if matters win 10 pro 64 with two gpus of 970 and 950 i7 devils canyon