yup. https://github.com/element-hq/element-x-ios/issues/3151 is a real wart; we're finally at the point now where the push notification process can synchronise with the main process to get the badge count right. Sorry it's taken so long to fix.
Folks keep saying that, but I can still never get rid of this badge. Even upgraded this morning. Is there _anything_ I can do by say, hopping on the DB and deleting rows???