I think there might be some issue with the 'banned for 10 minutes: Stressing Network' plugin. I've seen/experienced a rather rapid increase of this occurring lately. Maybe something to look into.
Not sure what's problem or potential fix or if there is anything anyone can really do.
But it seems quite random, since I've myself gotten banned after change map vote, ban happens whilst server change map, and it has happened multiple times without me doing anything.