Network Rail and train operators Southern and Thameslink are fully aware of the issues that caused the disruption to services into London Bridge from 5 January. Since that date they have worked closely to resolve these issues and improve reliability.
Network Rail, Southern and Thameslink have committed to incorporate lessons learned from these events into the planning of future phases of work at London Bridge. They will also incorporate lessons learnt from the disruption seen at Kings Cross and Paddington over Christmas and the recommendation included in the recent ORR report into these issues.
I do not consider a further investigation necessary.