Different wranglers have reported encountering these issues since the 29th of March.
Normally, after synning a tag in the edit page (by adding an existing canonical tag in the "Synonym of" box and saving, the fandom of the canonical tag will be attached automatically in the "Fandoms" box. After 1-10 minutes the works will show at the works page e.g. (edit page) (work page). Works would also show after canonising tags by ticking the "Canonical" box.
Occasionally we will encounter issues especially during high archive usage times. But for the most parts, everything takes after a few minutes.
However, for the past couple of weeks, works have repeatedly not show nor does the fandoms get attached. It takes many tries (manually desynning then resynning, or decanonising then recanonising) to get works to show, even during archive low usage periods. A staff also reported issues during staff allocated days (Wed/Fri).
For syns with more than one work, there are some cases where only some of the works show but others don't. Reindexing the works does not fix the problem.