Not able to save surveys after attempting to save without answering a mandatory question

I think there is a glitch in the system. We encounter that whilst doing a survey if someone by accident try to save the survey, makes impossible to save the survey at any other moment (“Sorry, you cannot save this entry until you reach the end of the form, because you have edited a ´jump question´”)

That is correct behaviour.

Changing a “jump question” answer could hide/show new questions based on its answer, so the user needs to reach the end of the form to fill in any new questions to be able to save the form again.

However, this should happen only when you edit existing entries. Could you please provide a way to reproduce it on a new (not saved yet) entry?

I understand now, effectively it is not an issue when you save for a first time the survey, but once you open it again and by mistake try to save during a mandatory jump question without filling an answer, the issue appears.
The main issue is that even if you do fill the question prompted as a result of the jump question, you are not able to save the survey anyway.

I think it makes sense that if you actually ‘modify’ a jump question after saving for a first time, it results in a limitation for saving (avoiding missing data), but I am not sure if there is a way to avoid the issue when no changes are made to the jump questions.

Correct, you still need to reach the end of the form to save the edit. This is not ideal, agreed, but due to the dynamic nature of Epicollect5 forms, it is the more consistent and robust way to make sure all the new questions are answered (or skipped) correctly. Changing a jump question might create a domino effect on all the questions after that, something kinda hairy to deal with automatically, hence the reason for the user to reach the end.