

I hope someone is able to tell me what is going on here....
I have made a 4k 60PFS recording on my iphone 8 plus.
The file properties of this mov file is around 42 MB an the Bitrate is around 39000 KBPS..(see photo)
When this file is uploaded to Google Drive the file properties stays the same...(as expected)
However !!!
When I upload this file to dropbox the filesize became around 64 MB and the Bitrate has changed to 57000 (see photo)
The uploaded file is terrible to watch .... stuttering and stuttering etc....
Why is this changed after the upload to Dropbox ?
I would expect no modifications.
Have tested this a couple of times with the same outcome everytime.
Anyone ??