The Mask of the Demon is on German channel...

The Father Brown is quite popular this autumn. "The Mask of the Demon" is on ZDF NEO channel on 6 October.

https://www.youtv.de/tv-sendungen/2054966-father-brown

I wish I could write something new, but unfortunately I have no news about Jonathan.
Take care of yourself!

The mask of the Demon (Father Brown) is on....

... on Alibi channel on 11 September at 1.00 pm and 8.00 pm (UK time).
https://www.tvguide.co.uk/detail/2273669/141998003/father-brown

Wishing you a bright and beautiful Autumn!