Recently I started using Ubuntu 25.04 and my Scroll Lock button stopped working. As I need it to light my keyboard, I tried adding "modifier_map Mod3 { Scroll_Lock };" at /usr/share/X11/xkb/symbols/pc, then tried sudo dpkg-reconfigure xkb-data and rebooted my PC.
It simply worked, however I don't know why, is there a permanent solution? Why it worked?