Contact deleted in Sailfish side doesn't get deleted in Android side
First, I installed aliendalvik. Then, I deleted three contacts via Sailfish Contacts. Strangely, these contacts remain visible to Android applications. I've tried installing an Android Contacts application and deleted the contacts there, but they reappear instantly. I've tried rebooting, I've tried waiting for a (long) while in case some process needed to catch up, but nothing works, the contacts always reappear. I presume this is a bug, where the Sailfish and Android contacts databases for some reason only synchronise new contacts, but not deleted contacts.
This is the case on both a Jolla 1 and Jolla Tablet, on the latest versions of Sailfish with the latest versions of aliendalvik.
See the answer by @nas below for a workaround.