Some translation files are incomplete
de.po contains 176 strings, pl.po only 173, but German (de) and Polish (pl) are both fully translated according to Transifex.
For instance, "Zoom desktop with mouse wheel" is missing in pl.po despite being translated over a month ago. Even worse, an English string "Cycle through minimized windows in most recently used order" is missing even in Transifex (so it cannot be translated)!
Sadly, some other packages have that issue too.