Windows client 3.0.1 hangs after uploading 2 files with end-to-end encryption

Server V 19, Windows client 3.0.1 End-to-end encryption app installed and activated.
I create a user account via browser, create the same account in the client, the synchronizsation directory on the Windows PC. In the client I activate end-to-end encryption, create an empty directory and configure it to be encrypted. Then I throw about 10 GB data into this directory and expect synchronization. After uploading one directory and 2 files in it the process halts, no upload activity can be seen in the network card status window and after a few hours I give up. I delete everything from the first directory, force synchronization and it seems to believe me. Then I throw only one directory with 18 files into the first directory. After creating the dir and uploading 2 files, the process halts again and nothing happens.

I create another user account, enter it in the client and do not activate encryption for it. Then I throw in the 10 GB data and the upload starts swiftly, also visible in the network card status windows.

Any idea that I have made a mistake? Does the end-to-end encryption work for everybody else as the support of the commercial provider tries to convince me?

https://cloudlogin.world4you.com/index.php/s/roe8dB0EFiqs9pq/download

contains the log files of the Nextcloud client 3.0.1
I am using 2 accounts, one without E2EE which I have halted during recording logs. The other is with E2EE activated, it halts after transferring a few files/dirs. My commercial provider cannot help any more…

I have received the advice of a big commercial nextcloud-provider: E2EE just does not work reliably with client 3.0.1 and server version 19 yet and it is not advisable to use it for important data. Ok, I will forget about E2EE and Nextcloud working together.

Same with Windows Client 3.0.2
Fresh installed Client 3.0.2
Fresh account in a big German commercial Nextcloud service version 19.03
E2EE app 1.5.2 activated
New directory on Windows
Encryption activated for this directory
30 directries with files in it copied to this directory
Synchronisation starts in client but halts after creation of 2 encrypted directories on the server side.
E2EE just does not work…

After booting PC and Nextcloud Client this morning another 5 directories werde uploaded, thereafter client hangs saying “wait”. No other account is connected with this client installation. Am I the only user experiencing this?

I’m expieriencing a similar issue on two self hosted nextcloud servers (both running in Ubuntu 20.04.1, one installed a snap, the other “manually”. Version 20.0.1, Client version 3.0.3 (Windows 64 bit).

It just says “wait” in the client (no matter if Windows, macOS or Linux, no matter if over internet or in a gigabit LAN).

Pretty anoying actually. Especially if you consider, that nextcloud discourages the use of it’s internal encryption module and other products like seafile have encryption available by default. There you can also open encrypted files in the web interface by a set password.

My solution is still using Goodsync as synchronisation client, not the proprietary Nextcloud client. Goodsync has an encryption feature. Also very useful for all other kinds of synchronisation jobs between a wide choice of other server protocols beyond WEBDAV. It also has a lot more configuration switches than the proprietary client. Not free but worth the money in my opinion.