Hi,
I am using Roseta’s child theme CODEX and unfortunately I have the same issue. I can only view the frontend of my homepage (and blog page) once, after that, it keeps loading and loading without end as described by BSobek. It is not until I clear my browser cache that I have the chance to visit the frontend of my homepage again. But – again only once… The problem occurs not only with Firefox, but also with Microsoft Edge.
I have deactivated all my plugins and I have tried to install “Enable jQuery Migrate Helper” – unfortunately without success. So it seems to be a problem with the theme…
I hope you can fix it as soon as possible, at the moment the theme is of no use for me! 🙁