Connecting MacBook air to a Samsung monitor using a thunderbolt
Yes you can use a Samsung or (almost) any monitor with a Mac.  You don't have to use Apple monitors.

What does &quot;1028&quot; mean?   What is the native resolution of the monitor?  For example it might be FHD 1920x1080 or 1280x1024 or 4K etc.   If you don't know then what is the make and model?

If possible, connect your monitor to another computer or to a TV device like a Roku, cable box, etc to see if the monitor works nicely with those or if it shows the same problems with any device, in which case it might be defective.

Go into System Preferences --&gt; Displays and see that the resolution is set to &quot;Default for Display&quot;.   The preferences tool may look like one of the following.   Note I have not chosen &quot;Default for Display&quot; for one of my monitors .... but you SHOULD choose it as a starting point to get the best results.