Using data modify to set the name from a block only works once

# initialize
scoreboard objectives add tmp dummy
scoreboard players set @p tmp 1
summon armor_stand ~ ~ ~ {CustomNameVisible:1b,Tags:["tmp"]}

# loop
setblock 0 0 0 minecraft:spruce_sign{Text1:'{"score":{"objective":"tmp","name":"@p"}}',Text2:'""',Text3:'""',Text4:'""'}
data modify entity @e[tag=tmp,limit=1] CustomName set from block 0 0 0 Text1
setblock 0 0 0 minecraft:air