Sorry, I do not see any issue
 

except the missing classification of the 16 and 17 years old participants
and there were no quotas.

But I am wondering why you use an assignment in the equation.
It is sufficient to use {if(age.NAOK>59,"xxx",if(age.NAOK>47,...
This way the value is stored in a variable with the name of the equation (agegroup)
Your syntax is used when you want to assign something to a different question, e.g. presetting it.

Is it really necessary to have a text as classification.
I think you will use it later in your analysis, e.g. to calculate an ANOVA or other statistical tests.
Wouldn't it be better to use numerical codes.

Or coming back to the assignment, create a (hidden) question of type "list(radio)" called "agegroup"
with the answer options
1 : <18
2: 18-24
3: 25-34
...

and in the equation (called "EQagegroup") you assign the value:
{agegroup=if(age.NAOK > 59, 6, if(age.NAOK > 44, 5, if(age.NAOK > 34, 4, if(age.NAOK > 24, 3, if(age.NAOK > 17, 2,1)))))}

Joffm


 

I had a look at the first file you sent and there are a couple of things wrong. You allow age 16 and above, but you do not have any age category defined for age 16 and 17. So if you put 16 or 17, nothing will show up.

off-topic:

Your LimeSurvey version: Versão 3.19.1+191009

In times of data protection laws like GDPR and in your case LGPD you really shouldn't run such an old version of a software that potentially collects personal data. Your installation hasn't been updated since October 2019 and thus has not received any security updates or bug fixes since then.

I highly recommend to update your installation to at least the lastest version of the LS 3.x branch, which today is 3.28.1 (from 29/02/2022).

Thank you very much, Joffm.

In these new 'agegroup' and 'EQagegroup', should I keep the relevance equation as 1 or should I asign the code to it?

Also, only in the test my peer sent you the merging is working well. Although she copied the two questions from the original survey, in the original, the same previous code comes like this:

 

Do not copy images into the editor, it will just give weird code here in the forum.

I just fixed it

Always a good idea to delete the redirect to your panel provider...

For me, the information seems to be saved just fine:

 

Tested with the lastest version of LS 3.x
Version 3.28.1+220229

Thank you for the tips, Holch!

Yes, but only in this copy we created to send here. We imported and exported the original survey, and then deleted the other questions. Still, same age and agegroup question and coding and the agegroup answers come as the code we assign...

We´ve had other surveys with the same questions and length and this is the first time we are experiencing this issue.

In both of your files I don't see anything e3xcept that you obviously changed the equation a bit.

@holch already showed our reesults.

Here a sample of my idea.
 

Thank you for the sample. 
It works with the new answers. However, I imported the vvfile with previous answers and only a few responded to it, as in the attachment bellow: 

 

Well, then something was wrong in the previous question. But as we do not have access to this, we can't tell.