As of version 1.17.1, players must have their feet in water to begin swimming

Prior to 1.17.1, the only requirement for players to begin swimming was having their eyes submerged. However, starting from 1.17.1, players also need to have their feet in water. This adjustment has made it harder to build sound spamming machines. To overcome this, players must leverage MC-224410. Furthermore, this modification prevents players from initiating swimming if they stand on non-waterlogged, non-full blocks underwater, such as dirt paths, mud, enchanting tables, and similar blocks unlike before 1.17.1.