I’m not very good at English but let’s try to explain.
With the “exam” mode, the dotted lines are in front of the answers when there are fractions.
Is there a solution ?
This seems to be an issue in the implementation of the macro
gap-dots-short in https://github.com/texmacs/texmacs/blob/7f904cb56e043708eb6f1bfe25e57d237610448d/TeXmacs/packages/standard/std-edu.ts#L514
It looks like just superposing dots on the answer. I don’t know whether it is possible to implement this using