Experimenting with Nextcloud sync. Set up to sync with a new (empty) folder.

Until now I haven't been able to transfer more than approx. 10-20% of my data. Every time it encounters an error on an arbitrary file (Error encountered transferring files: ...) and aborts.

When I restart the sync, it reports that it cannot find a library and starts all over again. And then fails again at some other file.

I noticed that the upload speed is horribly slow. Half an hour for 10% of the data... Average 5 seconds per file transfer regardless of size. For comparison, when I backup to Nextcloud uploading the complete backup (340Mb) takes less than a minute. The tablet has a strong WiFi connection (5GHz band, 866Mbps transfer speed).