[solved] Can't upload (new) files via desktop client

I’m using the desktop client in version 3.4.2 on a Xubuntu 22.04. I’m connected to two independent nextcloud servers and with both I’m facing the following issues:
I cannot upload new files via the client. I don’t receive any error – it’s like the client pretends that nothing happened. However, I may successfully create new folders, edit existing files, rename existing files, delete existing files, download files from server and receive updates on files. The webinterface is working fine too.

Would not updating to the current desktop client version be the first step? That would be 3.10.

Indeed, integrating the stable-PPA ( sudo add-apt-repository ppa:nextcloud-devs/client -y) allowed me to upgrade to 3.10 and resolved the issue. Thanks Sven!