Scaling Samsung Curved Monitor and Macbook Air 2014 (Thunderbolt to HDMI)

Hi,

I'm currently running a 13- inch Macbook Air 2014 with macOS Catalina (10.15.5) and connecting it to an external Samsung Curved Monitor CF390 (24 inch) through the thunderbolt and a thunderbolt to HDMI adapter. Using both the Macbook's display and the Samsung (not mirroring)

When I first installed everything, I had to adjust the image on the monitor so it wouldn't have some "black edges" al around the image. After updating the software, the setting were turned back to factory and I can't find my way back to fitting the display. I have black edges all around the display image.

I have already tried:

• Pressing the options key to get more scale options
• Every combination between 50 and 60 Hertz and all the scale options.
• Changing the monitor setting from Picture = Auto to Picture = Wide (and trying all the combinations of scale again)

Any ideas on how to fix it? Or anyone with a similar setting know how to fix this?

I'm adding screenshots of the system preferences on both displays that might help.

Thank you very much.