Track fault at Oxford Circus

[xtmw]

What has caused this issue to occur 2 times within a month?

I recall it shutting down the Victoria Line between Victoria and Warren Street about two weeks ago, and happened again today, suspending the service between Warren Street and Brixton.

Victoria Line: No service between Warren Street and Brixton and SEVERE DELAYS on the rest of the line while we fix a track fault at Oxford Circus. Tickets are being accepted on London Buses.

[seaeagle]

From what I understand it was a different failure to the last one, just happened to be in the same area.

[plasmid]

I was wondering if there was any updates regarding the speed restrictions in place at Oxford Circus southbound as this has been going on for quite some time. Trains queue as far back as Highbury & Islington at peak times and are start/stop all the way until past Oxford Circus.