Daylight Saving Time (DST) Not Observed in Year 2021
Windhoek currently observes Central Africa Time (CAT)
all year.
DST is no longer in use.
Clocks do not change in Windhoek, Namibia.
The previous DST change in Windhoek was on 24 October 2017
Do you have documentation for the final change being on October 24th? The database has the change occurring on September 3rd 2017. If there's appropriate documentation showing that it actually changed on October 24th, it would be good to update the database accordingly.
But other than the precise date, what you've described is what the rules show as well. The 2017 part of the rules that Arthur Olsen included before means that those rules terminate in 2017.
From the final change in September 2017, Africa/Windhoek is on UTC+2, with abbreviation CAT.
2017-09-03 01:00:00Z +02:00:00 standard CAT
Because the time zone database covers the past as well as the future, and Africa/Windhoek used to alternate between CAT and WAT.
Why it is different from other rule and format?
Which specific other rule and format? It's not clear to me what you mean, but I don't believe there's any problem here.
Jon