Just because Electra jailbreak for iOS 11 is now available with Cydia installed doesn’t mean everything will work accordingly. Users are now able to add repositories, install tweaks, and themes. But you may find a few Cydia tweaks that aren’t working on iOS 11.
Saurik is still working to get Cydia updated for iOS 11 along with Substrate. As a result, the tweaks you installed may not work or show up in the Settings app as a preference page.
In case of event like this, here’s how to resolve the issue.
How to Fix Cydia Tweaks Not Working on iOS 11
Step 1: Check to see if PreferenceLoader tweak is installed on your device. If not, you will have to get it from Ryan Petrich’s repo at https://rpetri.ch/repo/.
Step 2: Respring your iPhone or iPad
Step 3: Re-enable Electra jailbreak
PreferenceLoader allows developers to add options to your Settings app. Hopefully, by installing the latest version of this tweak, other Cydia tweaks that you have installed will work and appear in the Settings app.
As of right now, Cydia is still unstable. Errors are expected to occur. Your best bet is to install tweaks that are compatible with iOS 11. You can also install tweaks manually via these methods.