System font bolded gets larger point size in Linuxin recent IDEs

This is really quite annoying: in 2024r4.1, if you have some text (say, in a DesktopLabel), and leave it as System font, default size (i.e., left at 0), but then set it bold, under Linux (only) it becomes a lot wider. In 2023r4 it does not.

Consider these images. This one is under macOS (Sonoma 14.7.2):

Now the same, but running under Linux Mint 20.3 Una:

Now we see that with the current IDE, the default font under Linux is a bit larger and, when bolded, wider too:

Anyone know what’s going on? Doesn’t affect macOS or Win-10.