Your jars may have stalled, I would trying shaking the jars. Also stalling can occur if its not getting enough air, I had some jars stall/ slow in growth because I had waaay to many dust/contam barriers in place( typical verm layer, tyvek layer, polyfill layer, micropore tape, coffee filter, and kept them in a tubberware ) when I remedied this they took off growing again.
But I wouldnt birth them at 80%, you would be sure to contam.