K8400 Printing Problems with dual extruders

Hello Community,

i have a problem with the K8400. We have a Dual Head and we use Verbatim Filament ABS.

Everything is fine but if we print with dual extruders the second extruder ( The Left One) won’t heat up in the next layer. I think the the problem is the firmware? he holds the temperature of 210 ° but still wont heat up to 230 ° like in the past.

Additional: is there a way to prevent cooldown?