Your LimeSurvey version: 5.3.13  (php 7.3.33)
Own server or LimeSurvey hosting: Own
Survey theme/template: fruity
Plugins: hideEmptyColumn / limeMpdf / pdfReport
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I have 3 active surveys with a lot of responses, but I have an important problem. Some responses are marked as 'finished', but the last page is 0 and there are not all answers to the questions.
The survey is ending even though the respondent completes all pages/questions.
But this happens to some respondents, not all.

Can you help me?

Usually a survey is not marked "finished" if the respondent does not reach the end page.

Also, this sounds odd: "but the last page is 0 and there are not all answers to the questions."

This means the last page registered is basically the beginning of the survey, but they have moved forward because they have answers, correct?

Indeed, the first page of the survey, after the welcome page, is one of the last registered pages. I reorganized questions and groups. A weird thing is that most respondents go through every page of the survey correctly. For some, the search stops midway, as if it's over. The respondent receives a confirmation email and this response is marked as 'finished' but incomplete (the last page is marked as 0 in the database). It's a headache because I need to edit each answer from a participant to mark it as 'not finished' so they can complete the survey.

Is it a bug of Limesurvey?
Do you have any suggestion?

It might be a bug. Please report it and give a link here.