After a bunch of tests, we managed to find out that the cause of the disconnects is the treasure coffer. When it appears in the radius of loading / visibility of the player, it will cos of instantly disconnect. Apparently, the problem appeared only on the Microsoft store client (everything works fine in my Steam), it became relevant yesterday at 18:00 server time (immediately with the start of siege time). It is highly advisable to fix this as soon as possible, because it can be used against entire clans if their players play through the microsoft store client or similar. The issue is reproducible on official servers, but not in single player, which suggests that it is not a corrupted file (checking local files does not reveal any problems)

ALSO: His unconscious body becomes invulnerable to any damage up to a scheduled restart or server crash. After a server restart / crash, it is vulnerable for some time, but only if it does not try to enter the game. At the same time, attempts to kill him, as a rule, after some time drops the entire server.