nextcloud sync shows offline

Hi

I have installed filerun on IIS server with PHP 7.4

I have installed nextcloud on ubuntu as well as android, how ever both devices are not syncing. desktop is showing offline, while android is not showing anyfile in folder after log in. screenshots attached. I have also shown dav.php. Please advise. 

I have tested demo server and its working fine.

Regards

Asim

https://loh.meethizindagi.org/dav.php/

XML

Desktop
Desktop

Android