CAS command question

[compsystems]

I have noticed that the CAS history works different to the execution of a CAS program

The first step before programming is to test the sequence of steps of the algorithm on CAS history

CAS MODE

s := "(1/3)*x+(1/6)*y<=80"; ⇨ "(1/3)*x+(1/6)*y<=80" // ok
expr( s ); ⇨ expr( "(1/3)*x+(1/6)*y<=80" ) ⇨ 80 ≥ (1/3)*x+ (1/6)*y // ok
left( expr(s) ); ⇨ expr( "(1/3)*x+(1/6)*y<=80" ) ⇨ left( 80 ≥ (1/3)*x+ (1/6)*y ) ⇨ 80 // ok

left( expr( "'"+s+"'" )); ⇨ left( expr( "'"+"(1/3)*x+(1/6)*y<=80"+"'" ) ⇨ left( '(1/3)*x+(1/6)*y<=80' ) ⇨ (1/3)*x+(1/6)*y // ok

left(expr("'"+s+"'")) ⇨ (1/3)*x+(1/6)*y // ok

Now step by step

expr( "'"+s+"'" ); ⇨ (1/3)*x+(1/6)*y ≤ 80 ⇦ It has removed the quotes (Apparently well.). The quotation marks must be preserved
the next step fails Copying to the entry line
[up] [copy] [enter] 80≥ (1/3)*x+(1/6)*y (wrong for the above reason)

expr( "'"+s+"'" ); ⇨ '(1/3)*x+(1/6)*y ≤ 80' // This is the correct output

An easier example
HP-PRIME
3+4; [ENTER] 7 // ok
'3+4'; [ENTER] 3+4 (Apparently well.).
[up key] [copy] 3+4 [enter] 7 // wrong

This should be copied with quotation marks, or better with the function QUOTE()
[up key] [copy] '3+4' or quote(3+4) [enter] '3+4' // ok

HP50G
'3+4' [ENTER] '3+4' // ok
[up or HIST key] [copy (right-shift+var)] then [on] [paste] [ENTER] '3+4' // ok and not 7