Problem loading Numbers or Pages files

We use OS Mojave 10.14.3. We already discovered many problems uploading. After many hours it had uploaded a number of files but the folders had no content. I decided to do things slowly and tried uploading folder by folder, this will take ages but I thought it was working. However I now discover that all the Pages and Numbers files have a message that there is no preview available and to download. Is this normal? and does anyone know how to resolve it so the files can be accessed

Hello tio,

As thumbnails of “.pages” & “.numbers” files are not supported by My Cloud Home, that’s why you are getting an option to “to download” only. These files need to download and open in their native supported application.

https://support.wdc.com/knowledgebase/answer.aspx?ID=18574