Multitasking
I can use slide over but I can’t use split view, why is that?
iPad mini 2 Wi-Fi
Question marked as
The tags appended to your post suggest that you have an iPad mini2 - which can only be updated to iOS 12.5.1.
The iPad mini2 lacks the system resources to run split screen. Full multi-tasking features require an iPad capable of running iPadOS13/14.