First, check that your test reference amperage is correct so that you are not trying to over set the meter to compensate for a low test amperage. Also test the meter at different scale selector range maximums to determine that there is a consistent meter maximum reading accuracy or error across all selector settings. I would also recommend checking the meter's fuse contacts for any oxidation.
If there are issues found there and there is no erratic indicator motion; then, the moving of the spring end connection to the adjusting screw may have affected the spring's action (these very low rate clock type meter springs are very delicate). I had a similar problem with a VOM, when trying to adjust it, the needle action was free but became very erratic for no apparent reason; but, after a few repetitions of gently rotating the adjustment screw back and forth and resetting it to the correct position the problem disappeared. So you might try that.
If that does not correct the problem then wearing of the indicator shaft ends creating friction in the jewel bearings may be the problem; or, the needle return spring may be weakened or damaged; and, as a result, when you lower the spring tension with the adjusting screw enough to allow the indicator to reach the required scale maximum value, then there is not sufficient spring tension left to return the indicator to the zero point. To test for that, I would reset the indicator to a lower scale value and see if the indicator then moves closer to the scale zero point.
If so, then the spring has probably lost some of its tension or the indicator shaft is worn and replacement of the meter is going to be the best bet; but, depending upon the meters replacement cost, you may want to contact the meter mfr or try to locate a qualified meter repair facility before buying a replacement meter.