Florian, Just FYI, mine is doing exactly the same. I upgraded this morning to stable using the upgrade script with no errors. When I check the LetsEncrypt box and save, all is well ... the config updates with correct ssl locations and certs are put in /var/www/clients/client5/web23/ssl/hostname-le.crt (-le.key and -le.bundle) Next trip back to the UI, the box is unchecked and if I change something else about the config and forget to go back and recheck the LE box, it reverts to the old self-signed cert. Separately, I went into the database and forced it to ssl_letsencrypt='y'. It stayed that way for a minute or so and then went back to 'n'. This is not a problem for me now that I know to re-check the LE box. Let me know if there is anything I should check to help out. Gareth.