2209WA, PSM after 2 minutes

Despite my settings in Windows 10, my screen enters the PSM (power saving mode) after +/- 2 minutes. I'm using a DVI to HDMI cable. And I have two displays connected to my HP ProBook 430 tablet with Intel HD 5500 graphic card. It only goes into PSM when I'm not doing anything and getting out is not a problem. It only goes to fast. When I get a coffee and come back I have to login again, which is annoying. Can someone help me? 

I'm not using the battery, just power supply

I just noticed that it's not always two minutes, sometimes much longer