I don’t use Memories, but yes, uploading photos with FolderSync to Nextcloud (via WebDAV) does add them to the Nextcloud database. They show up as new photos in the recent activities list.

buttons were discovered by the Conbee and worked perfectly fine, but the home assistant refuses to recognize their functionality.

That’s not the hardware stick; that’s the controller software stack. Sounds like you switched from deConz to ZHA to go with the hardware change. In which case, this is all fixed by using Zigbee2MQTT instead of HA’s built-in ZHA. Z2M supports more hardware and features than ZHA.