It might be that these steps weren't done correctly.
First, choose a high-pass setting for printing — for example, 8-pass — which produces finer detail than lower-pass printing.
Second, appropriately increase the feathering level. This helps reduce the jagged edges.
Third, switch to unidirectional printing for critical images. Although the speed will be a bit slower, the details and overall effect will be better.
Fourth, don't overlook software updates. Keeping your software up to date ensures smoother transitions with new algorithms.
Fifth, add one extra step before printing: clean the surface of the material to remove dust and grease, which improves ink adhesion.