Plot hole: When the DigiDestined return to the real world, Izzy states that only a few minutes have passed by despite the weeks that have elapsed in the DigiWorld. However, in an earlier episode, Tai returns to the real world for hours and upon his return to the DigiWorld, only a few weeks have passed by.
Plot hole: In each episode, Emmy, and Max travel to dragon land (often for a long time) without their parents ever knowing. This makes no sense. Their parents would notice sooner, or later that Max, and Emmy always go in, and out of the house, or that it's always quiet in Emmy, and Max's playroom. You'd think Emmy, and Max's parents would get suspicious, and would question their children accordingly.
Plot hole: Sydney is able to surmise from the artwork (we could also say from the writing, but her rival is one step ahead of her for 2/3 of the episode and it is established that he does not know the language) the precise location of the koi in Lumbini. The map is 150 years old, but there's no way even with a big stretch of imagination to buy that they both'd be able to pinpoint with such ease and certainty its location in the basement of a random building in the bustling market center of a town, that surely changed plenty during the past century and that does not bear any special landmark.