Nextcloud client keeps going offline

I’ve just added about 50GB to a client’s Nextcloud system - a mixture of Office files and videos. Nextcloud is (slowly) working it’s way through them uploading to the server, but is it normal for the client to keep going offline?

It starts again but not sure if it’s actually uploading? It keeps getting 400 Bad Requests?

Later… turns out it’s just not working. I’ve deleted all the files from the the two new group folders as this is just the seed process of moving a folder from a personal area to a group folder. Will leave it to see if it manages to get back to empty folders. All it seems to have done so far is upload the folder structure.

The Nextcloud client keeps “not responding” as well…

Later… in the end I had to restart the entire Linux server as Nextcloud simply would not synchronise any changes. I need to dig deeper into this because these problems with synchronisation crop up now and then. Error 404, connection closed etc. Something isn’t scaling/working correctly.