@GrandDynamo said:

Season 2 should be removed. abema, also wikipedia numbers them from 1 - 24, Amazon lists them from 1 - 24, rakuten also lists them as 24 episodes. I think it is safe to say that it should be 1 season consisting of 24 episodes.

You are wrong! It is 2 Seasons! See here: https://www.anisearch.com/anime/10084,gate/relations

The secons season is called Gate: Jieitai Kanochi nite, Kaku Tatakaeri (2016) / GATE 自衛隊 彼の地にて、斯く戦えり (2016)