The numbering doesn't update if you delete previous cells, rather than simply editing the text.
So if for example you typed some cells (1-6) out but then decided you wanted to change them. So rather than editing the existing 1-6 cells, you make new cells (7-12) and delete the old ones. The columns rows would now begin with 7, and 1-6 would no longer exist. You can see the attached images below in which I create a loop and merge, then delete rows 2-6, making the rows read as: 1, 7, 8, 9.

https://community.qualtrics.com/XMcommunity/discussion/comment/43696#Comment_43696Thank you! This is a little bit annoying given the fact that you don't pay attention to it while creating your survey and adapting items several times. Maybe I need to rebuild the survey then.

https://community.qualtrics.com/XMcommunity/discussion/comment/43739#Comment_43739I agree, it is annoying, especially if you need to reference the loop&merge factors in a particulary way. I haven't checked it personally, but you may be able to reset this through some combination of copying/cutting the right text out the loop&merge, clearing out the loop&merge entirely, turning loop&merge off on the block, duplicating the block, deleting the original block, and then turning loop& merge back on in the new, duplicated block. In theory, the new, duplicated block could now begin with 1 and you can simply paste in the correct versions. You would then need to check survey flow to make sure the new block is in the right place, branching, etc. To do this after multiple edits is still annoying though. So perhaps start in an excel sheet until you are happy with it.

wpm24 I guess I will see in the end when I won't change anything what I will do. Thanks for your advice!