Hey @Moto, 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!
Below are some links to how-to’s answering frequently asked questions and may help you help yourself;
- How to install Nextcloud snap
- How to configure Nextcloud snap
- How to edit config.php for Nextcloud snap
- How to use OCC management console for Nextcloud snap
- How to revert Nextcloud snap after failed update
- How to manage failed automatic update in Nextcloud snap
- Nextcloud snap wiki and support
pay special attention to:
View apps in Nextcloud
sudo nextcloud.occ app:list
Disable apps
sudo nextcloud.occ app:disable <appname>
Remove apps
sudo nextcloud.occ app:remove <appname>
in your case
sudo nextcloud.occ app:remove spreed
alternatively see: