The bug

The scoreboard sidebar is supposed to align its numbers to the right side, touching the edge of the screen, like this:

However, this only works if the longest name on the sidebar is longer than the objective name itself.

If the objective name is longer than the longest name, the numbers are not aligned to the right, but are instead placed to the right of the longest name:

How to reproduce

/scoreboard objectives add test dummy a_very_long_scoreboard_name
/scoreboard objectives setdisplay sidebar test
/scoreboard players set blah test 5 

→ The 5 is not aligned to the right

Observed appearance

Expected appearance

You may also notice that there is padding missing between the longest player and their score: