I am using Nextcloud already since a long time and so far without issues. But recently my client (after upgrading the client) got stuck on checking big directories.
Server: Unraid with Nextcloud-Docker
Client: Windows 10 with Nextcloud Client 2.5.1
Directory: MAny images including Adobe Lightroom Directory Structure (120GB, 20k folders, 40k files)
I anyhow had to reinstall my windows so I tested from scratch. Initial Sync is working, but any following sync not.