You’re not the only one — what you’re seeing is consistent with how Semantic Search works today in ODC.

A few key points that explain your situation:

1. Semantic Search is a Beta feature and can change or disappear between releases
   In ODC, Semantic Search is explicitly marked as Beta, and both the Studio node and the generated backend artifacts can change or break between releases, even if your logic didn’t change at all.Semantic search in ODC apps
   There has been at least one case where a previously working Semantic Search node started causing compilation errors after an update, with no changes to the app, exactly because of backend updates to the Beta feature.Semantic Search node results in compilation error

2. The node’s behavior and availability can be changed by OutSystems updates
   Since it’s Beta:

   • The Semantic Search node in the toolbox can be renamed, moved, or temporarily hidden/disabled.
   • The backend search service and indexing contracts can be updated, which may lead OutSystems to adjust visibility of the node or roll out fixes that affect existing apps.Semantic search in ODC apps

3. What you can check right now in your environment Without asking for more assets, you can verify the following directly in ODC Studio:

   • Confirm your environment still has Semantic Search enabled Semantic Search requires that your environment is configured for the Beta feature. If your company/environment settings changed (for example, Beta features disabled or access removed), the node may no longer appear in the toolbox.Use semantic search

   • Check if your entities are still marked as searchable Go to Data tab → Right‑click an entity → “Select searchable attributes…”.
     If this option is missing or disabled, that’s a strong indication Semantic Search is not currently active in your environment.Use semantic search

   • Check the toolbox inside a Server Action The Semantic Search element only appears in Server Actions. Open a server action and search the toolbox (where you currently see Start, Run Server Action, Aggregate, JSON, etc.). If the Semantic Search node is entirely gone from there, it’s likely a feature-availability issue rather than something in your app.Use semantic search

4. Region / tenancy considerations Semantic Search has some regional constraints (because of the embedding model availability). In unsupported regions, OutSystems routes data to EU for embedding and back, but it’s still officially available everywhere.Semantic search in ODC apps
   If your environment was moved or reconfigured to enforce stricter data residency policies, your OutSystems admin or account team may have disabled this Beta feature.

5. Impact on token optimization and agent building For your Agent flow (like the one shown in your screenshot with CallClassificationModel), you’re using AI models and probably want Semantic Search just for grounding/token optimization over your data.
   Right now, if the Semantic Search node isn’t visible:

   • You can still proceed with direct model calls (CallTrialClaudeHaiku4_5, TrialGPT4o, etc.).
   • You won’t be able to use the built‑in ODC semantic search mechanism (vectors + indexes over entities) until the feature is re‑enabled in your environment.Semantic search in ODC apps

6. Whether it’s just you or everyone Based on previous reports:

   • Other users have experienced breaking changes and errors on publish when using the Semantic Search node, tied to platform updates.Semantic Search node results in compilation error
   • Fixes have been rolled out centrally by OutSystems, meaning behavior can change for all tenants at once.Semantic Search node results in compilation error

So it’s almost certainly not just you, but it may depend on:

• Your ODC region and environment configuration, and
• Whether Beta features (Semantic Search) are currently active for your tenant.

Next practical step:
Since this is a Beta feature and controlled per account/tenant, the most effective path is to:

• Verify “Select searchable attributes…” is still available on entities.
• If not, contact your OutSystems account team / support and explicitly ask whether ODC Semantic Search Beta is currently enabled for your environment and if there were recent changes affecting the node’s visibility.Use semantic search

If you tell me whether you still see “Select searchable attributes…” on any entity, I can help reason if it’s more likely a UI/node visibility issue vs. a full feature disable.