--- a/plugins/muc/muc.lib.lua	Tue Nov 16 13:53:30 2021 +0100
+++ b/plugins/muc/muc.lib.lua	Tue Nov 16 15:00:02 2021 +0000
@@ -1539,6 +1539,7 @@
 	if not data then
 		if value == nil then return true; end
 		data = {};
+		self._affiliation_data[jid] = data;
 	end
 	local old_value = data[key];
 	data[key] = value;