In vanilla 1.13, when you click on the banner while holding a map, it puts the banner location in the map. If the banner that was clicked on is named, the banner name will show under the map. This is a new feature in Minecraft 1.13.

However, in Spigot 1.13, the banner name does not show in the map.

How to reproduce:

1. Start and login into the server
2. Create a map
3. Rename a map using an anvil
4. Place the banner down (on ground or wall doesn't matter)
5. Right click the banner while holding the map in hand.

At this point (in vanilla), the banner's name and the banner itself should show on the map. However (on spigot), only the banner icon shows.

As always, thank you for all your hard work!