I'm not super well-versed in computer hardware, but here is my issue.

Two Dell monitors were displaying correctly on OptiPlex 9020 Mini-Tower. The Mini-Tower has 3 DP interfaces, 1 VGA, and 1 DVI. Each monitor had 1 VGA port and 1 DVI port. One monitor was plugged into the DP interface on the Mini-tower with a DVI cable that used a DVI to DisplayPort adapter. The second monitor was plugged in using a DVI cable.

I'm switching these older monitors with two E2216H monitors, where each monitor has 1 VGA port and 1 DP. The only way either monitor will display is if it is plugged into one particular DP interface on the Mini-Tower (the same DP interface that the previous monitor used). Neither monitor will be recognized if plugged into the other two DP interfaces. Instead I get the message "Entering Power Save Mode". Right now I have one E2216H monitor plugged into that DP interface and it's displaying well. I've tried connecting the second monitor into the VGA interface and the DVI interface (using both a DP and a VGA adapter). Unfortunately, I keep getting the "Entering Power Save Mode" message.

Hopefully I gave enough information. Any help is appreciated. Thank you.