I do think you need to change the bearing!
I cannot say for sure about the DP-E, I have a DP-D1 and it does NOT have a zerk fitting, they changed the bearing to a sealed bearing. It was a "6206 2RS" IIRC.
As I stated in a previous post, I had to replace mine because of a bellows leak. It’s pretty easy once you get the drive off. There is an external snap ring that holds a plastic spacer, then the bearing. IIRC,there was an internal snap ring that held the bearing on the shaft.
I would dry lube or anti-seize the shaft splines (both ends).
Hope this helps