Errore 500 interno del server usando l'assistente AI "Suggerisci titolo"

I temi correlati sono simili, ma questo sembra nuovo. Tutti gli altri temi correlativi sono stati contrassegnati come risolti.

TLDR: errore 500 quando si suggerisce un titolo per il tema.
(proofread, generazione di tabelle Markdown, suggerimento di tag, embedding e ricerca semantica funzionano tutti correttamente)
Self hosted v2026.10.0-latest +401, droplet Digitalocean e inferenza serverless, Deepseek 3.2 tramite endpoint DO.

I log generano l’errore:

Failed to process hijacked response correctly : NoMethodError : undefined method 'flatten' for an instance of String
/var/www/discourse/plugins/discourse-ai/lib/ai_helper/assistant.rb:202:in 'DiscourseAi::AiHelper::Assistant#generate_and_send_prompt' 
/var/www/discourse/plugins/discourse-ai/app/controllers/discourse_ai/ai_helper/assistant_controller.rb:65:in 'block in DiscourseAi::AiHelper::AssistantController#suggest_title' 
/var/www/discourse/lib/hijack.rb:68:in 'BasicObject#instance_eval' 
/var/www/discourse/lib/hijack.rb:68:in 'block (2 levels) in Hijack#hijack' 
i18n-1.14.8/lib/i18n.rb:354:in 'I18n::Base#with_locale' 
/var/www/discourse/lib/hijack.rb:68:in 'block in Hijack#hijack' 
concurrent-ruby-1.3.8/lib/concurrent-ruby/concurrent/promises.rb:911:in 'Concurrent::Promises::Event#callback_on_resolution' 
concurrent-ruby-1.3.8/lib/concurrent-ruby/concurrent/promises.rb:797:in 'Concurrent::Promises::AbstractEventFuture#call_callback' 
concurrent-ruby-1.3.8/lib/concurrent-ruby/concurrent/promises.rb:803:in 'Concurrent::Promises::AbstractEventFuture#call_callbacks' 
concurrent-ruby-1.3.8/lib/concurrent-ruby/concurrent/promises.rb:692:in 'Concurrent::Promises::AbstractEventFuture#resolve_with' 
concurrent-ruby-1.3.8/lib/concurrent-ruby/concurrent/promises.rb:1331:in 'Concurrent::Promises::ResolvableEvent#resolve' 
/var/www/discourse/lib/scheduler/defer.rb:135:in 'block in Scheduler::Deferrable#do_work' 
rails_multisite-9.0.0/lib/rails_multisite/connection_management/null_instance.rb:54:in 'RailsMultisite::ConnectionManagement::NullInstance#with_connection'
rails_multisite-9.0.0/lib/rails_multisite/connection_management.rb:23:in 'RailsMultisite::ConnectionManagement.with_connection'
/var/www/discourse/lib/scheduler/defer.rb:130:in 'Scheduler::Deferrable#do_work' 
/var/www/discourse/lib/scheduler/defer.rb:116:in 'block (2 levels) in Scheduler::Deferrable#start_thread' 

Fammi sapere se posso aggiungere altre informazioni.