OK, I also found this: https://tvshowscancelled.com/expedition-unknown-renewed-for-season-6-by-discovery/ It says via Travel Channel that Season 6 was set to release on April 7th 2019 with an episode titled "Egypt Live". This was published about a month prior to season 6 starting. It's officially stating that would be season 6. This also pre-dates the other contrary source by almost a year. So this was the channel's original intention for the season order.

As indicated above by @banana_girl , we should respect what the network has done at the time of the release.

Ok. Good. I was hoping you'd understand. Now we have proof that tells us the network made this season 6 at the time of its release, not the 4-part special that currently is listed. The source originally cited is from 10 months later so we can safely ignore it now that we know it was a fluke.

@samuraicyclist said:

Ok. Good. I was hoping you'd understand. Now we have proof that tells us the network made this season 6 at the time of its release, not the 4-part special that currently is listed. The source originally cited is from 10 months later so we can safely ignore it now that we know it was a fluke.

Your article doesn't proof anything. It was written after the release of the 4 episodes. So, it doesn't indicate anything about the way they were initially released.

I understand that. However, the single source... the ONLY source that says the four episodes were season 6 came from July 2019. That is after the source I provided. So, there are no sources from the time of release that day those four episodes were a season. Zero evidence. Then, we have a March 2019 source saying that the season airing in April 2019 was season 6. That is as close to original as anyone has produced. Everyone keeps saying that tmdb cares about how it was originally released. I can't understand why one single source from 10 months later is somehow closer to original than one that is only 6 months later. I don't think it takes too much imagination to believe that the stuff in July was an error. I mean, they took it down 2 weeks later.

Here is an archived page of the official site from October 2018 (at the time of the release) that clearly indicate that "Search for the Afterlife" was released as season 6.

We can't go against this.