My problem arose because of typing the space after the dot.
This was done by clicking
- the downward arrow in the Multilevel List icon
- Define New Multilevel List...
Doing this opened the window named "Define new Multilevel list". Then I added a space in "Entering formatting for number:". This was my mistake. Whenever anything else that a single dot is added to the number in "Entering formatting for number:", que character (e.g. a space) will appear as part of the cross reference.
When I erased the space from "Entering formatting for number:", and chose "Space" from the drop-down menu under "Follow number with:", the problem was solved. Now, when I cross reference an item of the list, I do not get even the dot that follows the number by default.
In summary, use the "Follow number with:" drop-down menu from the "Define new Multilevel list" if you want to have a space after the dot that follows the number of a numbered list.