Here is the deal
I have 4 boxes wired to 3 monitors. One is connected to all for using HDMI switch and to the other two using DP 2-1 switches. 2 other boxes connect to two monitors - HDMI and DP (left and the other right). The forth box is just connected to the HDMI
The DP switches would send inactive signal to the PC, but my main 4-1 HDMI swich would not.
Is there something I am missing here?