Hey @wpender, welcome to the Nextcloud community and thanks for supporting Nextcloud snap 
Sorry to hear you are having issues with your Nextcloud snap installation. If you’ve come this far, you’re on the right track! There is a good chance someone in the community has had a similar issue and knows how to resolve it.
In order to help you we’ll need some Information to get an Idea of your setup, so complete the required support template and post the output of the following command allowing us to look at your redacted configuration file:
sudo nextcloud.occ config:list
Nextcloud logs are very verbose, thus your logs will certainly help resolve your issue. access your logs by following how to manage Nextcloud snap logs or you could run the debugging script and post the result here or paste the result of the following command:
sudo tail -n 20 /var/snap/nextcloud/current/logs/nextcloud.log
Below are some links to how-to’s answering frequently asked questions and may help you help yourself, especially the last link should be helpful;