If it is a different brand of hose , it maybe thicker . I have buffed the rubber off where the fitting screws on , to allow theouter part of the fitting to screw on .
cat hydraulic fittings are what is known as skive type fittings ie outer rubber should be removed for the length of outer fitting.
The way I remember doing them is measure the amount of thread on the outer sleeve,transfer that measurement to the hose end,then peel off the outer layer of the hose that amount,screw on the fitting to the hose (it is left hand thread) till it butts,put some oil in the hose bore and dip the inner fitting in oil then screw it in (it is right hand thread) and tighten it up against the outer sleeve.
AJ