I have a Nextcloud 19 docker installation on a VPS with Backblaze B2 configured as primary storage. Server side encryption is enabled. I uploaded some files (around 22GB) using the Nextcloud desktop client (version 3.0.2) on Windows 10. When I checked the Backblaze data usage details, it showed an equivalent increase in download. To confirm that this is not an anomaly I checked the data transfer on my VPS provider and it too showed an increase in incoming traffic for the similar amount of data (excluding the amount of data from my desktop to VPS).
What is causing the download when the files were only uploaded? Is this expected?