Microsoft Sentinel: Watchlist synchronization issues — inconsistent behavior and delayed updates

Question

Problem description

I'm experiencing inconsistent behavior with my Microsoft Sentinel Watchlists. Although the watchlists are successfully created and appear correctly in the 'Edit Watchlist Items' section, after more than 24 hours, the portal shows zero rows for new watchlists, the '_GetWatchlist' function returns zero records, and some deleted watchlists continue to appear in the '_GetWatchlistAlias' results. Additionally, discrepancies exist between the number of watchlists shown and the watchlist items displayed. I am seeking assistance to understand and resolve these synchronization issues.

Environment

Microsoft Sentinel in an Azure workspace, functions involved include _GetWatchlist() and _GetWatchlistAlias(), scenario is in a single workspace. Specific region or SKU details are not provided.

What I've already tried

I recreated the watchlist, verified that items appear in 'Edit Watchlist Items', and observed the issue after more than 24 hours. I also noted that the support conversation did not record troubleshooting actions beyond the initial report. I reviewed self-help materials indicating that watchlists are scoped to the same workspace, and that cross-workspace scenarios are not supported. No other troubleshooting steps have been documented.

Current status

The issue persists with inconsistent synchronization between watchlist creation, display, and function results. I am seeking guidance to identify the root cause and implement a solution to ensure proper synchronization and data reflection in Microsoft Sentinel.