After several tests I have found that it is the MFE that gives me an error, since I have deactivated it with these options in this post, users can enter the course without problems.
But as it says right there in that post, it is not recommended to disable it since it has not been tested.
On the other hand, install tutor in its lilac 12.2.0 version and it works perfectly.
I have tried to see the mfe logs but I can’t find it, since unfortunately both the lms and caddy logs don’t say where the mfe fails when rendering the course