A piped text with loop & merge fields function doesn't work at all.

Hi all,
I am a newbie to Qualtrics, so I am not sure whether I coded incorrectly, or there is some issue on looping.
By following the instruction of this link, https://www.qualtrics.com/support/survey-platform/survey-module/editing-questions/piped-text/piped-text-overview/#PipingFromALoopAndMergeField
I set some loop protocols as below and tried to loop a block several times and inserting piped texts with loop & merge fields like below,

On the loop & merge page
I keep the box "Loop based off of a question:" unticked.

Field 1
row1: samsung galaxy s5
row2: apple iphone 6
row3: nokia lumia
row4: htc one

"Randomize loop order" box was ticked with
Present only 1~4 of total loops. The inserted number doesn't affect anything.


Then, on each question, I coded as below,

Q1.
Have you heard of the ${lm://Field/1}?
Q2.
Do you own the ${lm://Field/1}?

However, when I checked its preview, the "${lm://Field/1}" part is empy on preview screen and even a there is no loop and only show the above Q1 and Q2 once.

I checked the other Qualtrics functions and when I inserted piped text of random number, or date, etc, it's working properly.

Only the problem is inserting piped text of loop & merge field.

Please let me know how to solve this problem!