Earlier today it was fine, the main screen was perfect and the lilliputs were perfect. Somewhere along the line something is causing the main screen to ignore the 2560x1440 line and it's going 2260x2240... Tomorrows another day, i'll keep plugging away! Thanks for the help!
Went on "derammo's Discord channel and asked about the issue, here is the response - "In the Interface dialog called "DCS Monitor Setup", click on the "plane and helicopter" on each of the extra monitors to turn them from "blue" i.e. included in the view of the sky to not blue"... DUH, it worked!!