Client synchronisation pending

We have a Nextcloud hosted by IndieCloud, we are ok with their online service but they are in trouble with the clients. From the beginning we are in trouble with the local clients.
We have PCs both on Linux (mainly LinuxMint) and Windows and we had several different problems, the last one and not yet solved is that on certain machines (Linux and Windows) the client stays in the synchronization preparation phase and never synchronizes with the server.
We upgraded all the clients to last nextcloud versions (2.3.1 on windows / 2.3.2 on linux) and that problem is still here, I can’t explain why. And the support doesn’t know which version I should use (owncloud, nextcloud, another webdav client?).
Thanks for any help!

You can try a webdav client first, if it works or not. If it doesn’t work, there is a setup problem and you don’t get proper webdav and the clients won’t work either.

On the client side, Nextcloud does only branding, though in the packaging there are still some problems with OS X and they tend to lack a bit behind. F11 opens a logging windows for more errors. For everything else, you would need logs from the server.

Hi Thank you for your reply.
I tried the integrated linux webdav access and that works perfectly.
There is really a synchro problem with the client. I can add a detail : in the local interface of nextcloud client I have the details of the server activity up to date but I have nothing in local activity tab, and no file is downloaded or uploaded