Thanks for sharing your solution.
You can also just paste complete URL on the login dialog, like this:
https://example.com/nextcloud/remote.php/dav/files/NEXTCLOUDUSERNAME/
https://winscp.net/eng/docs/ui_login#pasting

So what i was missing was to set the Directory

When creating Session – after selecting File Protocol as WebDAV and filling in other details, the Host name box should contain only the domain name.

• Press the ‘Advanced…’ button
  
• Navigate to ‘Environment’ > ‘Directories’ on the left side
  
• Fill in the ‘Remote directory’ field
  

What is to be filled in ?
Well this depends on the WebDAV server you are trying to access.
For NextCloud it is - /nextcloud/remote.php/dav/files/NEXTCLOUDUSERNAME/
replace NEXTCLOUDUSERNAME with your nextcloud username

For cloud storage of my email provider it is docs/USERNAME
replace USERNAME with your email id without domain name.

Version 6.3.1 (Build 14821 2024-02-21)
This is Portable Version
OS - Windows 11 22H2

Issue: WinSCP connects to WebDAV server but files are not seen.

For the same WebDAV account I can connect and see files, copy / paste as well on another system, version on that system is 5.17.10 (installer version) on Windows 10 1511.

Am I missing some settings here?