The movie that gets me is this group of people gets stranded on a jungle island. There’s something in the water that kills people, maybe a mutant octopus. They pick a bunch of fruit and bananas, and overnight there’s this weird music sequence while the fruit pulsates. When they try to eat the fruit in the morning it’s all filled with like purple paint or something. Then they discover some old science lab and one guy gets sort of a reverse amnesia where he forgets the present around him and starts remembering the past when he apparently worked there.
“Danger Island”, also known as “The Presence” (1992 TV movie)
https://www.imdb.com/title/tt0104049/
Detailed plot description on Wikipedia here:
https://en.wikipedia.org/wiki/Danger_Island_(film)