My guess? The ad tracking is a daemon regardless, but when you disable it regularly it disables the daemon. However when jailbroken, there may be code within the jailbreak or an assumption within the OS code that has two processes fighting over starting it and stopping it.
For example the jailbroken code might have something that tries to keep all daemons running and the OS sees the ad one running and tries to kill it.
For example the jailbroken code might have something that tries to keep all daemons running and the OS sees the ad one running and tries to kill it.