Do you have official proofs that these episodes were broadcasted as a single double-length episode ?

Yes, IMDB and TVDB listed them as such:

• Exit9B
• Terror Tales of the Park II
• The Christmas Special

If you need more proof the intros of each episode doesnt indicate that they are divided in two parts:

• Exit9B
• Terror Tales of the Park II
• The Christmas Special

In addition if you search for the episodes there isnt any clue that they are divided in two parts, in fact HBOMax has them as a single episode.

IMDB and TVDB aren't official sources.

We need proof about the original broadcast, not the current ones.

@superboy97 said:

IMDB and TVDB aren't official sources.

We need proof about the original broadcast, not the current ones.

You have a problem then, because you listed a similar episode as a single part instead of two, that episode is the S03E04, Terror Tales of the Park, that has a similar runtime to the ones mentioned above.

Unfortunaley I dont have official proof about the original broadcast, the only airing proof of the original is from unofficial sources so it will stay like this.