Access to same variable twice without change it, get different outcome

[Ghostfish_]

{exist.%player%} is set under the code below

on join:
    if {exist.%player%} is not set:
        set {exist.%player%} to true

command //setUpFormerExisted:
    permission: tbc.excommands
    trigger:
        loop all players:
            make console execute command "//setUpExistance %loop-player%"
        loop all offline players:
            make console execute command "//setUpExistance %loop-offline player%"

command //setUpExistance [<text>]:
    trigger:
        if arg 1 is set:
            set {exist.%arg 1%} to true
        else:
            set {exist.%player%} to true

function isPlayerExist(p: text) :: boolean:
    broadcast "{exist.%{_p}%} is %{exist.%{_p}%}%"
    if {exist.%{_p}%} is true:
        return true
    else:
        return false

The problem is that if I access the variable {exist.Ghostfish_} through my account named "Ghostfish_", I will get the result of true
And if I log on to another account named "test", I will get the result of false. The same thing happened to {exist.test}

I tried to access to the variable {exist.test} through this command /gv by "Ghostfish_", I will get true

command //getVariable <text>:
    aliases: /gv
    permission: tbc.excommands
    trigger:
        send "%{%arg 1%}%"

How should I fix it? Thank you guys very much!
[doublepost=1605219949,1605219872][/doublepost]"The problem is that if I access the variable {exist.Ghostfish_} through my account named "Ghostfish_", I will get the result of true
And if I log on to another account named "test", I will get the result of false. The same thing happened to {exist.test}"

Through method isPlayerExist(text)
[doublepost=1605220685][/doublepost]Here are the screenshots
will any invisible information be generated by subtext? By invisible information, I mean something like "<reset>1" will look exactly the same as "1" but actually different

if loop-value contains "@":
                set {_si} to the first index of "@" in loop-value
                set {_si} to sum({_si},1)
                set {_ei} to length of loop-value
                
                set {_targetText} to subtext of loop-value from characters {_si} to {_ei}
                delete {_target}
                set {_target} to {_targetText} parsed as player
                
                delete {_pre}
                set {_pre} to subtext of loop-value from characters 0 to subtract({_si},2)
                if isPlayerExist({_targetText}) is true:
                    set {_post} to "<light blue>%subtext of loop-value from characters subtract({_si},1) to {_ei}%"
                else:
                    set {_post} to "<reset>%subtext of loop-value from characters subtract({_si},1) to {_ei}%"
                    
                if {_pre} is set:
                    set {_rp} to "%{_pre}%%{_post}%<reset>"
                else:
                    set {_rp} to "%{_post}%<reset>"
                set {_nm} to "%{_nm}%%{_rp}% "
                
                if isPlayerExist({_targetText}) is true:
                    aitPlayer_inChat({_target}, {_targetText}, {_p}, {_m}, getTime())