The actual size of the file is 495GB, notice that when the upload reaches about 350GB / 495GB, the file size increases, in this case it is already 846GB.
RClone does not support uploading a large file of 495GB?
No source file is increasing in size. Possibly upload fails and restic retries letting you know that overall transferred data amount increases. The exact answer will be in debug log.
If you need more help please answer all questions you were asked when creating this thread.
This happened to me when I was uploading to OneDrive and the duration exceeded 24 hours. From what I have researched, it appears to be that it is Microsoft that has set the maximum validity period for their OneDrive token to be 24 hours.
When the 24-hour period was reached and the token expired, RClone wouldn't fail and stop; rather, it would start a new transfer of the same file but the new file size would be the original/real file size plus whatever amount had been transferred at the time of the token expiration.
So, for example, I had a 123GB file to upload and after 24 hours, only 95GB had transferred. When it started the new transfer of the file, the file size was showing as 123GB + 9GB = 218GB.
Cloud storage services can also implement per file size limits, for Onedrive that is 250gb. Thats why there was questions when starting a topic, for example what storage provider are you using?