Elden Ring has received a minor hotfix, which you'll need to install in order to continue playing online. The main target of this hotfix seems to be what you can see in the video below, where a lategame boss essentially disappears halfway through the fight—now why didn't that happen on my runthrough?
Radahn glitched and just disappeared mid fight! The summon NPCs kept fighting the air! #ELDENRING #glitch pic.twitter.com/Ds5rfPAl66March 19, 2022
This is one of several ways in which the Radahn boss fight can glitch: I've also seen a rather spectacular clip of him dive-bombing to his death into the water around the arena, which is perhaps not the most fitting end for a god.
Anyway, the hotfix should stop bosses dying "at unintended times," as well as addressing a bug where Malenia wasn't healing correctly in multiplayer. Finally on bosses, the Elden Beast would apparently just... stop working under "certain circumstances" and you could wail away for a free win. No more: the Elden Beast is back.
There are also some minor fixes: the Cerulean Hidden Tear item now lasts the appropriate length, and some unspecified textual errors have been corrected. The update takes Elden Ring to version 1.04.1 (notes here), and in a rather charming sign-off Bandai-Namco promises future updates "so you can enjoy Elden Ring more comfortably." Perhaps 1.04.2 will improve my chair's cushioning.
Don't expect a major update for another while: version 1.04 only arrived about a week ago, and made a huge list of changes (including patching Patches). Elsewhere in Elden Ring, a player's found a mysterious colosseum that may well be intended for DLC, someone's making a Game Boy demake (!), while others are somehow creating mini-armies of summons to pulverise bosses. Times are good in the Lands Between, even if the PC version's performance issues remain a drag.