This due to MATLAB not supporting high DPI monitors on Linux platforms.
MATLAB's definition of a normal DPI monitor is 96 dpi (dot per inch). Any monitor with higher resolution (for example, 144 dpi) would be a high DPI monitor.
In such cases, MATLAB should paint everything 50% larger (144/96) so that on a high DPI monitor, the desktop and figures would look crisp and be sized normally. This is currently done for Windows platforms, but this does not apply to Linux systems.
There are a few workarounds for this issue:
1: There could be some incompatibilities on the 'libc' and java-version. Try installing the package called 'matlab-support' to replace the 'libc' packages. You can do this by following the steps on this MATLAB Answers post:
2: Change the fonts of individual MATLAB components. From the Home Tab, choose Preferences > MATLAB > Fonts.
This works better than scaling down the native resolution of a high-DPI monitor as the smaller figures and items do not evenly correspond to the number of pixels in the monitor. To produce something smaller than the monitor's native resolution, the display must interpolate (scale) the item to be larger and fill the screen which is why the display might not be crisp.
3: From the Home Tab, choose Preferences > MATLAB > Fonts. Check the box for 'Antialiasing to Smooth Desktop Fonts'.
4. Use a monitor with lower native resolution.
5. Set the 'FontSmoothing' axes property to 'off'. It is 'on' by default.
The link below contains more information about MATLAB's DPI-aware behavior:
