problems with 2 external monitors via DVI on M4700

On my M4700 with K1000m I wanted to connect two external monitors via the docks DVI. The laptop is closed.
Windows 8.1, 32 GB RAM.

I can only activate one of the monitors. If I try to activate both I get only flickering - screen switching on/off, I can see the mouse cursor briefly.

I then disconnected one DVI and connected this monitor via VGA - both now work.

The dock appears to be a PR02X, unsure about USB3, two dual DP-DVI ports, both DVI were used.

The switchable graphics in BIOS are off.

What is wrong here? This setup should work on the M4700 as only 2 monitors are in use.
Could the laptop itself be defective?

This is company equipment. The dock has already been replaced, no change.

 

This "should" work. I can confirm that I have used the same configuration with the Precision M6700 and Precision M4800 without any issue or hassle. Precision M6700 in particular is very similar to the M4700.

You could try using DisplayPort off of the dock instead. (DisplayPort to DVI adapters are easy to find and cheap.) There's a chance that would work better...

 

Thanks

The problem is, sometimes I am in our other offices. Then I am using a shared workspace, where the 2 monitors are connected via DVI.
I don't want to juggle cables all the time