Font blurry with external display on macOS Sierra

Hi, I have a MacBookPro with Retina display connected to an external display (LG23EA53) with a thunderbolt-dvi cable. If the display is connected when I open a new document or sheet with LibreOffice (Version: 5.3.1.2) the font looks blurry. That happens only when the external display is connected and when the window is on the built-in display. If I unplug the display I have to restart the LO app to get it work again.

Normal display without external monitor:

Blurry fonts with external monitor:

I had the same problem but found I could fix it by toggling off the “Direct Cursor Mode” in the Edit Menu.