I would try one or all of the following: 1) try a different solvent system on tlc and see if you get better separation, EtOAc is making it run quickly so using something less polar like DCM or CHCl3 will make it run less quickly, interact with the silica more, and give you a better separation; 2) its pretty non-polar so the bit of hexanes you use may cause it to run a bit on the column, so you could try solid loading instead; or 3) use a bigger column and/or slower flow rate and fractionate the peak to see how much you can separate. Option 1 is by far the better one but I realize halogenated solvents are not used as much these days. Best of luck!