Hi I have 2001 XJ, oil change I used 5w30 valvoline months ago when I had done my previous repairs.
I bought the jeep used and it would leave puddles everywhere it went. I would occasionally leave a drop or two after repairs but now it’s a bit bigger.is there another seal that I cannot see that needs to be replaced. Previous seals I replaced did need attention
I have replace Power Steering lines
Felpro rear main seal and oil pan gasket
Felpro Valve Cover Gasket
Felpro Oil Filter mount seal
Chrysler Drain Plug

 

These old 6's were designed long before 5W oil was even thought of. 10/30 if you want to use multi grade or 20W in the winter and 30W in the summer. From the image, it looks like you rear main seal is leaking. Take it back to the shop that replaced it, or if you replaced it maybe you should find an experienced mechanic. Jeeps leak - my guideline is not to worry about it until it leaves rude reminders that you've visited. Note, with the poor quality of replacement parts, leak repairs come back to hunt you within a few years anyway