The FA 2018 lecture is used here.
The differences between the FA 2018 Study Notes used in the lectures and those you are using for FA 2019 are as follows:
Example 4 – change to date of disposal but no change in answer as it is the same indexation factor from date of acquisition to December 2017
Example 5 – change to date of disposal but no change to answer.
Example 6 – change in dates of purchase and sale but no change to answer as same indexation factor used from date of acquisition to December 2017