There are no missing seasons. There is a three season gap between the original seasons and new seasons that TLC currently uses. This is because TMDB does not re-order the seasons when the network re-arrange their past seasons.

If you want the alternative order that is currently used by TLC, there's an episode group for it: https://www.themoviedb.org/tv/34045-sister-wives/episode_group/5ae93165c3a3683bac002f3e

There is no three season gap. Discovery (TLC) own website shows all 19 seasons in the proper order. https://www.discoveryplus.com/show/sister-wives?season=19

That's exactly why there is a gap!

Absolutely everywhere, including Wikipedia the TLC website and every other website on the planet state that there is 19 seasons, so none of this makes any sense that you guys have it capped at 16 seasons, App Store, error and judgement that you are making

This is not a judgment error, but an application of the rule.

For all our series, we follow the way the episodes were originally released. We never reorganise the seasons when the network decide to completely change them.

As indicated, you have an episode group available for the current order.

I understand the rule, and I support following the way the episodes were originally released to remain consistent with the rule. But should that not apply to the new seasons? For example, the latest season (season 19) was originally released as season 19, not season 16.

Listing it as season 16 seems to contradict the rule, since that's essentially saying that it would have been season 16 if TLC stuck to their original schedule, which they didn't.

A potential half-way solution is to just have a gap at the time the seasons were split. For example, if original seasons 2, 3 & 5 were later split into two seasons each, they can remain as they were originally released, but then the seasons released after the split should be listed as they were originally released. For example, 1, 2, 3, 4, 5, 9, 10 etc.

Additionally, having the official posters directly contradict the season name feels a bit off i.e. Season 6 poster saying "Season Nine.

@Bambanah said:

I understand the rule, and I support following the way the episodes were originally released to remain consistent with the rule. But should that not apply to the new seasons? For example, the latest season (season 19) was originally released as season 19, not season 16.

Listing it as season 16 seems to contradict the rule, since that's essentially saying that it would have been season 16 if TLC stuck to their original schedule, which they didn't.

As indicated in the rule : "When seasons are re-organized, for example after a network change, (e.g. American Dad, Futurama), we do not re-arranged the aired seasons/episodes. The new season is simply added as the next season."

A potential half-way solution is to just have a gap at the time the seasons were split. For example, if original seasons 2, 3 & 5 were later split into two seasons each, they can remain as they were originally released, but then the seasons released after the split should be listed as they were originally released. For example, 1, 2, 3, 4, 5, 9, 10 etc.

This way of doing thing can work only in cases were the previous seasons have been split in more seasons, like here or Futurama.

But, that doesn't work in series like American Dad, where previous seasons have been merged, in which case we will have multiple seasons with the same number.

The advantage of our rule is that it is working in the 2 cases.