Remington rolling block singel set trigger

[Rawlins78]

Hello!
I have a Remington no1 rolling block sporter with a single set trigger, but it is not working the way it supposed too.
It's working fine when not using the set trigger, but when I push the trigger forward and then pull the trigger, the hammer will not drop.
I have taken it apart and cleaned it.
I do not think anything is broken or any parts missing.
Hope someone here have the same trigger and maybe have a idea what is wrong.
Maybe some have a picture of a single set trigger?

Thank you!