Error 500 interno al usar la IA «Sugerir título de tema»

Los temas relacionados son similares, pero este parece ser nuevo. Todos los demás temas relacionados están marcados como resueltos.

Resumen: Error 500 al sugerir un título de tema.
(Proofread, generar tabla markdown, sugerir etiquetas, embedding, búsqueda/semántica funcionan correctamente)
Autoalojado v2026.10.0-latest +401, droplet de DigitalOcean e inferencia serverless, Deepseek 3.2 a través del endpoint de DO.

Los registros generan el siguiente error:

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' 

Avísenme si hay más información que pueda añadir.