Hm... Like some have already guessed that there's a connection between the recent TOS change.
If other third party client access is affected too, then this would suit these changes.

It's sad to see Livejournal makes a coexistence that hard, after all those years where it worked somehow, but this seems the "new way" things are.
Hopefully there will be a pathway in the long term that shows up through which the interoperability can be picked up again...