I just installed yEd 3.22 on a 14'' notebook with a full HD screen resolution (1920x1080), running Xubuntu 22.04.
While yEd seems to be running fine it is almost unusable due to the microscopic text size (< 1.5 mm?) of the UI.
I looked for solutions and found:
I added "
-Dsun.java2d.uiScale=2.0" to the starting line in the yEd starter script, and indeed, everything was scaled up, but far more than just twofold. Now everything was so big that, again, it is impossible to work with yEd. So I tried several values between 1.0 and 2.0. But even though the original hint suggests it, Java doesn't seem to honor the part of the values after the dot. So I get either too small or too large a UI.
I also tried the solutions suggested in your FAQs section ( https://yed.yworks.com/support/qa/2183/high-dpi-support-for-ui?show=2192#a2192 ), like
GDK_SCALE=2 /usr/lib/jvm/java-11-oracle/bin/java -jar /opt/yEd/yed.jar
But again, it is impossible to get a fractional scaling like 1.5x or similar. So I am stuck.