Redmine

After updating to Redmine 5.0.4 recently a redmine_checklists plugin (version 3.1.21) operations started to cause server error 500. It was noticed on adding a checklist to the new issue. But later it was found that in fact same error is logged on every item (checkbox) state change.
Error is

ArgumentError (:arguments expected to be an Array of individual string args)

More details:

I, [2023-01-05T23:43:05.965019 #3937]  INFO -- : Started PUT "/checklists/1/done" for 2a00::4837:572 at 2023-01-05 23:43:05 +0100
I, [2023-01-05T23:43:05.966362 #3937]  INFO -- : Processing by ChecklistsController#done as i
I, [2023-01-05T23:43:05.966430 #3937]  INFO -- :   Parameters: {"is_done"=>"false", "id"=>"1"}
I, [2023-01-05T23:43:05.986170 #3937]  INFO -- :   Current user: e (id=59)
I, [2023-01-05T23:43:06.100339 #3937]  INFO -- : Completed 500 Internal Server Error in 134ms (ActiveRecord: 40.0ms | Allocations: 29039)
F, [2023-01-05T23:43:06.101838 #3937] FATAL -- :   
ArgumentError (:arguments expected to be an Array of individual string args):

app/models/mailer.rb:709:in `mail'
app/models/mailer.rb:123:in `issue_edit'
app/models/mailer.rb:48:in `process'
plugins/redmine_checklists/lib/redmine_checklists/patches/compatibility/journal_patch.rb:65:in `block in deliver_checklist_notification'
plugins/redmine_checklists/lib/redmine_checklists/patches/compatibility/journal_patch.rb:64:in `each'
plugins/redmine_checklists/lib/redmine_checklists/patches/compatibility/journal_patch.rb:64:in `deliver_checklist_notification'
plugins/redmine_checklists/lib/redmine_checklists/patches/compatibility/journal_patch.rb:35:in `send_checklist_notification'
app/models/journal.rb:102:in `save'
plugins/redmine_checklists/app/controllers/checklists_controller.rb:127:in `with_issue_journal'
plugins/redmine_checklists/app/controllers/checklists_controller.rb:83:in `done'
lib/redmine/sudo_mode.rb:61:in `sudo_mode'
I, [2023-01-05T23:43:09.154643 #3937]  INFO -- : Started PUT "/checklists/1/done" for 2a00::4837:572 at 2023-01-05 23:43:09 +0100
I, [2023-01-05T23:43:09.155848 #3937]  INFO -- : Processing by ChecklistsController#done as i
I, [2023-01-05T23:43:09.155913 #3937]  INFO -- :   Parameters: {"is_done"=>"true", "id"=>"1"}
I, [2023-01-05T23:43:09.161977 #3937]  INFO -- :   Current user: e (id=59)
I, [2023-01-05T23:43:09.261213 #3937]  INFO -- : Completed 500 Internal Server Error in 105ms (ActiveRecord: 35.9ms | Allocations: 23339)
F, [2023-01-05T23:43:09.262602 #3937] FATAL -- :   
ArgumentError (:arguments expected to be an Array of individual string args):

app/models/mailer.rb:709:in `mail'
app/models/mailer.rb:123:in `issue_edit'
app/models/mailer.rb:48:in `process'
plugins/redmine_checklists/lib/redmine_checklists/patches/compatibility/journal_patch.rb:65:in `block in deliver_checklist_notification'
plugins/redmine_checklists/lib/redmine_checklists/patches/compatibility/journal_patch.rb:64:in `each'
plugins/redmine_checklists/lib/redmine_checklists/patches/compatibility/journal_patch.rb:64:in `deliver_checklist_notification'
plugins/redmine_checklists/lib/redmine_checklists/patches/compatibility/journal_patch.rb:35:in `send_checklist_notification'
app/models/journal.rb:102:in `save'
plugins/redmine_checklists/app/controllers/checklists_controller.rb:127:in `with_issue_journal'
plugins/redmine_checklists/app/controllers/checklists_controller.rb:83:in `done'
lib/redmine/sudo_mode.rb:61:in `sudo_mode'

Just for the case, the environment is:

Environment:
  Redmine version                5.0.4.stable
  Ruby version                   2.7.7-p221 (2022-11-24) [x86_64-linux]
  Rails version                  6.1.7
  Environment                    production
  Database adapter               Mysql2
  Mailer queue                   ActiveJob::QueueAdapters::AsyncAdapter
  Mailer delivery                sendmail
Redmine settings:
  Redmine theme                  Circle
SCM:
  Git                            2.38.2
  Filesystem                     
Redmine plugins:
  redmine_checklists             3.1.21

Actually, this looks like a bug...