RMVB 727 issue

UPDATE! Thanks to everyone who responded! Garrett, I did as you suggested in post #2 and put it into neutral after coming to a stop and noticed the shifter did'nt seemed a little off. I originally adjusted the shifter cable from p-r-n-1-2-3 and everything seemed spot on. I even rechecked this before posting here. But I noticed that when you go from 3-2-1-n especially from 2-1 the shifter was not putting the trans shift linkage all the way into 1st. so now an adjustment of the shifter cable should fix things until funds are available for a new shifter. I was planning on a new shifter anyways, so thanks again!