Welcome, Joe. I've a JD 2025R with similar issues. My JD 4010 (much like a 2019E, if one were made) front driveshaft Ujoint blew apart at 9 years and 660 hours. I let the 2025R go to 200 hours and then had the dealership pick it up to lube the Ujoints and to replace the PTO button (another recent issue with JDs). With the panel/cowling removed that covers the gauges down to the pedals to get at the PTO button, the techs could then remove the driveshaft to lube the Ujoints.
I had the same problem as you did with your front Ujoint zerk with the rear one. Just could not get a grease gun onto it and tried a couple of those needles, too. Can not really access the front one unless that panel/cowling that goes over the instruments is removed. Even then, you have to remove the shaft to allow the joints to be moved enough to get a grease gun onto the zerks.
I'll let mine go another 200 hours and then decide whether to have them do it again or trade for a Kubota B.
Ralph