Pics you need to host somewhere like flickr, and then link to them.
Yes what you describe is a sealed bearing. So the inside steal ring should rotate freely when the bolt is out. Now… here the group will split A bearing which does not rotate freely without the bolt will probably still rotate under the tension of the bolt. But it is obviously at a lower standard, and may be creaking. I wouldn’t say you need to replace immediately but it could be something to consider for the end of the year. How worth it often depends for me on how much of a PITA the frame is to change bearings. Many bearing only move through a few degrees and that rotation is kept free by frame motion.
It may have a 4 digit code on it. That is the number of the bearing you you need, Such as 6802. You may have a pivot that goes in the middle, very lightly grease the outside, not to lube, just to stop it seizing, but none on the bolt you put in either end.
Google your frame model and “bearing change”, may yeild some useful info too. What is the frame?
EDIT: ah!, that bearing sounds like it does need replacing, but on the flipside, should be easy to get out! Just check around where that bearing sits for any frame damage as well as I’ve never seen that before. Probably fine but worth a detailed look.