Fruits are made up of four groups. Acid fruits, sub-acid fruits, sweet fruits, and melons.
Typically you never want to mix any of the fruits with any other food group, each group should be eaten separately. Fruits travel through the digestive track very quickly, typically within an hour which is why you don’t want to eat them with other food groups.
From personal experience, I do notice that I feel better when I group foods together depending on how long it takes for them to digest. For example I would eat a pineapple and wait at least 30 mins before eating porridge or something else. However, this could just be a placebo effect as this is based on a theory, I don’t know of any scientific studies that support this. In fact, in an interview Dr. Michael Greger (Americal plant-based physician) himself said that food grouping is nonsense.