back in the time i use sailfish x on xperia x (free version) of course you can still update. but update on terminal not in setting, try this
devel-su
ssu release 2.0.1.11 (replace 2.0.1.11 with the update version you want or on your setting update)
version --dup
that will update your current os to the newest based on version you type on ssu release. CMIIW