Someone's been telling about eniripsa's absorption causing this, like, it's not the only class and passive that trigger the bug, but indeed, removing this passive from deck helped one of my teams to stop lagging every battle. If I'm playing with absorption, I'm getting bugs even solo. Another team doesn't even include eni, but still does get this bug occasionally (classes are iop x2, enu, cra, sram and trank). It's indeed hard to catch because it doesn't appear every single fight. Also the location might matter. I've been getting the most lags in xelorium past and present (both outside and dungeons).