The story
Blend of tricky + difficult. Alternatively, blend of triple + difficult, from the analogy of di- + fficult. The Rice University Neologisms Database listed the term since as early as 10 June 2008 as a blend of trying + difficult. Later popularised by a 2020 episode of the 2018 Australian animated children's TV series Bluey.
Etymology from Wiktionary, CC BY-SA 4.0.