I found this old link, the time line is shortly after Blackburn, CFPL TV and CKNX TV just left CBC and became independent. You can see the new logo for Blackburn at the start, and the New and last logo for CKNX when programing came out of Wingham.
When Baton (CFTO) bought the stations, programing moved to London the they changed to a single logo for both stations,

https://youtu.be/uxjs2zevsHo?si=UdLTa5y7F0NAmfLp