“Enable Custom Canonical URLs” missing

Hello, I was having problems with canonical URLs and pagination. Then I discovered something. The option “Enable Custom Canonical URLs” is missing from my admin. I discovered this because on another one of my websites that option is shown, but on the faulty one the option disappears as soon as I open the admin page (and for a brief moment I can see that this option is checked before disappearing).

I am using the Spanish latin american version of the plugin on the page with the problem and the english version of the plugin on the website that is working properly. Could this be the issue? Any suggestions? Thanks in advance