Usually when the 3 point and the loader don't work properly, the power beyond hose and the return hoses are switched. Been a year or two since I messed with a tractor that had a LA481 FEL on it, probably a L3010 or something?
On your loader hoses. Before you do anything else, switch the hoses. There are 4 of them, on quick couplers. Two on the left and two on the right. They are paired vertically, I.E. the right ones are for the lift and the left ones are for the dump. Switch them and see if the problem follows. Take the two on the left and put them on the right, and the 2 right ones go where you took the 2 lefts off.
If nothing changes then it's possible that PB (power beyond) and return hoses are switched, which would explain why the 3 point won't lift. PB feeds the 3 point. On the loader valve, they are marked. T (tank), BY (power beyond) and P (pressure). Those come from the tractor.