Rails 6.1.4.1 - Delayed Job 4.1.9 not processing jobs

[bh8ur8js]

I have complete and still working branch with the following settings

ruby 2.6.2

rails 5.2.4

delayed_job 4.1.8

#config/environments/development.rb

config.active_job.queue_adapter = :delayed_job
config.active_job.queue_name_prefix = "ukcil_#{Rails.env}"

#config/application.rb
#config/environments/development.rb
config.active_job.queue_adapter = :delayed_job

#Started with

bin/delayed_job -n 1 start

#Environment vairables are

RAILS_ENV=development
QUEUES=*

#config/initializers/delayed_job.rb

Delayed::Worker.queue_attributes = {
  mailers_h: {priority: 0},
  mailers_l: {priority: 10},
  general_h: { priority: 20 },
  general_l: { priority: 30 }
}

After upgrading to Rails 6.1.4.1 everything is working except for delayed_job.

Jobs are being queued correctly, appearing delayed_job_web front end view, as before

The delayed_job process is running, as per activity monitor, but the jobs are not being picked up and processed.

I just can't see what's changed here, are there any specific changes to the configuration needed for rails 6.1.4.1?

[bh8ur8js]

It was a very strange conflict with CSS-JSbuild processes. For some reason, the DJ will not get the jobs if those two processes are also running.