[Bug]: Federation worker stuck - activities not processed beyond ID 37575

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Summary

Federation is broken in both directions:

• Outbound: Posts/comments created don't reach other instances
• Inbound: Comments from other instances don't arrive on subscribed communities

Federation worker appears stuck, with all 3709 federated instances blocked at the same last_successful_id.

Steps to Reproduce

1. Create a new post on the instance
2. Check on other instances (lemmy.ml, etc) - post doesn't appear
3. Wait for comments from other instances on subscribed communities
4. Observe that comments never arrive, but new posts occasionally do

Technical Details

• Last sent_activity ID: 37608 (hasn't increased for hours despite ongoing activity)
• federation_queue_state shows all 3709 instances stuck at last_successful_id = 37575
• Inbox endpoint receives POST requests but comments aren't processed/stored
• Federate worker logs show only DB query operations, no actual activity sending
• Problem started suddenly ~9 days ago (2026-08-16)
• Both inbound AND outbound stopped simultaneously - suggests centralized bottleneck
• Persists with both single container and horizontal scaling setup

Version

0.19.20

Lemmy Instance URL

rollenspiel.forum