Hi @ecuris
Do you have backups of your 3.1.1.4 installation?
To be honest, I personally do not know how well OJS 3.3 works with PHP8. If you search the forums for PHP8 errors you’ll find a few others, like this one: Statistics not showing in OJS - #10 by jnugent
You could, in theory, set up a local webserver/PHP7.4 environment on your laptop or PC, create a 3.1.1.4 installation using your backups if you have them, and upgrade that to 3.3.0.7.
Regards,
Jason