T46S multiple line - on hold issue

[sprintership]

Experts,

i know I am missing something. I have three lines configured as:
linekey.1.value = 0
linekey.1.line = 1
linekey.1.type = 15
linekey.1.value = 0
linekey.2.line = 1
linekey.2.type = 15
linekey.2.value = 0
linekey.3.line = 1
linekey.3.type = 15
linekey.3.value = 0

If somebody 1 calls (line 1) I can put that on hold
if somebody 2 calls I cannot put that on hold = I can only swap it
if somebody 3 calls I can put that on hold

If I have all 3 lines I can all put on hold - how can I fix the option 2 with two lines = I would like to put second line on hold as well. I know I am missing something here.