I have something in a current project that should help you with this.
What you could do is in the level BP set up the trigger to make the platform show.
Use the “do once” node I believe it is, after the “begin overlap” and toggle visibility for the platform to show, set a delay for a few seconds and then toggle visibility again to hide the platform. And the output from the last visibility node, connect it to the “reset” on the “do once” node so then the player can activate the platform again. Then try deactivating the collision for the platform.