Second monitor, wrong resolution

for a while, I've been using a Dell E248WFPb (native 1920x1200) connected via VGA on my Dell Optiplex 7040 Micro successfully at it's native resolution. But I just moved the computer to another room, and now that same monitor is a second monitor to a Samsung 2343 (native 2048x1152) connected via DVI to HDMI adapter. The Samsung monitor runs great, native resolution and everything. But the Dell E248WFPb which is now a second monitor, I can't get to go to native resolution. Help!

Not sure if this will fix it, but first thing I would try is connecting it with something other than VGA, do you have any other options? DVI, HDMI, etc...?

I ordered a DVI to HDMI cable that hasn't arrived yet. I hope that will solve things. This computer only has DisplayPort, HDMI, and VGA ports, and the DisplayPort is already being used by the Samsung. I'll keep updated with the results.

I have a client that had the same issues and the only solution for him was using 2 identical monitors.

Well, I feel stupid. The problem has fixed itself after a restart. I thought I already did that, but I guess I only did the first boot with the monitors hooked up and didn't reboot after that, and it needed to configure things or something. So, problem solved! I got lucky and didn't have to buy a new monitor.
Thanks everyone!