Ipad System data size issue

I have an issue on my iPad mini 5 64GB. My iPad always show large files in System data which is 22.8GB. I already cleared each an everthing in recent files as well as unused apps. Further I deleted all photos and videos but its still showing. I updated my iPad on 16.4.1 an restore it as well but firstly its fine but when I download some videos the size of System Data again increased. Please fix it as soon as possible. I am unable to save more files on my iPad due to large size of system Data files. I hope Apple will help me and give a better option for not occure this problem in future.