According to Ch2 21:18., Joram died of a terrible disease, in which his bowels fell out, and was buried in the city of David, though not in the family sepulchre of the kings.
(Note: "The building of Carthage, Dido, her husband Sichaeus, her brother Pygmalion king of Tyre (scelere ante alios immanior omnes), all coincide with the reign of Joram. This synchronism of the history of Tyre is not without significance here. The Tyrian, Israelitish, and Judaean histories are closely connected at this time. Jezebel, a Tyrian princess, was Ahab's wife, and again her daughter Athaliah was the wife of Joram, and after his death the murderess of the heirs of the kingdom, and sole occupant of the throne.…
Rashi on 2 Kings 8:22
Livnoh rebelled. The inhabitants of Livnoh rebelled, and they rebelled against the king. I do not know from what nation they were, because Livnoh is part of Eretz Yisroel.25Livnoh is listed as one of Yehudah’s cities that were located at the southern extremity of Yehudah’s territory at Edom’s border. See Yehoshua 15:21, 42. But I say that they were of the tribe of Yehudah and they rebelled against the king.26Alternatively, Livnoh was an Edomite town close to the border, but at first did not join in the rebellion with the rest of Edom. However, after the war, Livnoh joined the Edomite rebellion.—Radak
Henry, Jamieson-Fausset-Brown, Clarke, Gill, Calvin and Keil & Delitzsch are in the public domain; Tyndale Open Study Notes © Tyndale House Publishers, CC BY-SA 4.0 — all from the Free Use Bible API (bible.helloao.org). Rashi: the Rosenbaum & Silbermann Pentateuch (public domain) and the Judaica Press and Metsudah Tanakh (CC BY), via Sefaria. Spurgeon's Treasury of David: public domain (lyteword's markdown edition, CC0).