Might be an issue with someone taking a positive reaction off a post of yours or changing a rating on a resource of yours. The latter, you can find out on your profile/notifications but for reactions you only get notified or get a stamp of that on your profile for given ones, not taken too. If removed, these reactions just disappear from your notifications/profile which impedes verifying if the system has bugs or not.
Since you get a notification for your level being lowered, you should also get one for why.
I suggest locking reactions after a certain amount of time so people won't do funny stuff. Might make it possible to change reactions again if the post reacted to was edited or if a resource reacted to was updated.