Try adding a 2.4uH coil across the feedpoint at the base of the antenna
and see if that helps.
That's a game saver at times. Like a small transformer.
If you have an MFJ 269 it will show what component of the SWR is making your readings high. Capacitive reactance or inductive reactance. The MFJ 259 can be helpful too but there's more a of a trick to it.