Mods like Shiny! Mobs can cause a conflict where a spawned mob is immediately transformed or removed. The gateway sees the "removal without death" and triggers an implosion.
This is the most common "hidden" cause. Many gateways (especially those from the Apotheosis mod) are hardcoded to spawn mobs that only exist in certain dimensions. If you try to open a "Sunlit Ascent" gateway in a Mining Dimension or a void world, it may implode because the game cannot find valid "invaders" for that specific dimension. Mods like Shiny