Size of uploaded folder differs from upload to upload

[JammingBen]

Describe the bug

I have a folder with 10 6 byte files, meaning the folder has a size of 60 bytes. When uploading the folder several times, the folders have a different size in the PROPFIND response.

Steps to reproduce

1. Create a folder with multiple small files, e.g. 10 6 byte files.
2. Upload the folder multiple times.
3. Do a PROPFIND on the parent folder and compare the oc:size properties in the response.

Expected behavior

All folders should have the same size.

Actual behavior

The size might differ from folder to folder.