The bug

There are two separate translation lines for the statistic for how many bells you've rung:

"stat.minecraft.bell_ring": "Bells Rung",

and

"stat.minecraft.ring_bell": "Bells Rung",

The first one, bell_ring, is the one used ingame, but ring_bell matches the format of the rest of the statistics. There's only one bells rung statistic ingame as well, so it's just the removal of unnecessary text from the lang files.