Please, please, please recode your pages/containers to elimante the hardcoded maximum display width of 1366 pixels. Very few people would work with a monitor with less than 1920x1080 resolution these days, many would be higher.
So much usuable screen space is wasted by squeezing your views into 1366 pixels, the split view option is almost unusable as each view gets about 680 pixels.
Flex containers will shrink down for those on 1366 pixel displays, please relax these outdated bounds and let us use our monitors to their extents.
Such a change will likely also reduce complaints about narrow column widths as less contrained flex containers will allocate more pixels to each column.
Cheers,
Simon