Problem while importing data

[Alfred-237]

I'm currently having problems importing the data in production mode.
Locally everything works fine. In production mode, I manage to import a file without any problem then a few minutes later, any operation becomes impossible and I receive the following error: Class "PhpOffice\PhpSpreadsheet\Spreadsheet" not found

it is then necessary to delete and upload again my project to see the system working again but just for a few minutes and a few tries then the same error message comes back.
Can you help me solve this problem?