Kenmore 80 Series top load washing machine

I have an old Kenmore washing machine. Recently it stopped agitating during the wash cycle. After looking at YouTube I realized my Dog Agits needed replacing, which I did and now it will agitate but only on the “wash” cycle, which is only a very short cycle. If I put it on “heavy Load’ or “permanent press” cycle it will fill but then the timer just ticks away, then it will drain and begin the rinse cycle. During the rinse cycle it agitates fine, so I know the recent repair I made corrected that problem, but I can’t figure out why it won’t agitate during the time when it is supposed to…please help.