Scoreboards don't correctly display values other than text (such as selectors or even other scores) in players' numberformats or names.

Steps to reproduce:

With a selector:

/scoreboard objectives add nearest_player dummy {"text":"Nearest player"}
/execute as @a at @s run scoreboard players display numberformat @s nearest_player fixed {"selector":"@p[distance=0.01..]"}

With a score:

/scoreboard objectives add money dummy {"text":"Money","color":"green"}
/execute as @a run scoreboard players display numberformat @s money fixed [{"score":{"name":"@s","objective":"money"}},{"text":"$","color":"green"}]

Observed result:
Name of the player doesn't show. Instead, it shows their selector

If it's a score what you want to show, it doesn't show anything

Expected results:
The player's name correctly shows and it says (in this case) the nearest player that isn't the own player
The score is correctly shown and it says (in this case) how much money the player has.