Fail to export file (IPad)

Fail to export video; English is not my mother tongue.

IPad 8; IOS 16.5.1(20F75)

MDM used by school.

Still have about 30G storage in iPad, while the video is only about 400mb.

Image are PNG, largest size 3840x3840, 27.6mb. Others are all standard 4k image. Image export from procreate.

Local save file, not VIP.

I expect this app can import and export high quality image. This is not my final stage yet and still have a long way to go, yet it cannot be exported already. I don't want to find school assistance unless there's something to deal with MDM system because they are quite irresponsible and tend to ignore art students. I hope you can just solve the problem.

I am a student and this video/project is directly affecting my public exam result so it is very important to me. I am in dire need of some assistance. 

Please email me ASAP.