Driveshaft question - Help Needed

[Mile High VX]

So I crawled under my VX to investigate something for another member.

I found that the cap has come off the end of the section of the driveshaft that hold the lube and has slung grease all over the undercarriage. The cap is at the back end of this section towards the rear of the vehicle.

Anyone else ever had this issue?

Can I just push the end cap back in place and lube it again? I can move it and wiggle it to slide back into place but not sure if it will stay.

Here's a photo:



Thanks for the help.