WCML South delays

[Omnishambles]

Just travelling on the 1907 from Euston tonight with a crawl following no train between Camden and West London Jn. Looks like the last 5 or 6 departures have lost around 4” presumably with this too.
Long speed restriction or big signalling restriction??
Clues welcome

 

[BG2024]

Defective track between Euston and Watford Junction

 

[Omnishambles]

Defective track between Euston and Watford Junction

Not seen that of that is the generic National Rail announcement. To me a track defect would suggest something over West London Jn itself which wouldn’t necessitate such a long lead in from South Hampstead in my experience ?? ….unless an odd plain line defect