It was random probably with some race condition, connectors send sometimes last progress update after cancel and it causes the invalid UI state that seems like progress stuck in UI.
Removed unnecassary dup code in bindings, even function names was wrong.. i.e. OnSendProgressUpdate in Receive binding.
Added cancellation token cancelled? check to prevent progress update for any reason. I believe this is the safest fix for now.
It was random probably with some race condition, connectors send sometimes last progress update after cancel and it causes the invalid UI state that seems like progress stuck in UI.
OnSendProgressUpdate
in Receive binding.